diff --git a/lib/includes/spdylay/spdylay.h b/lib/includes/spdylay/spdylay.h
index 94f17cf..9758e5a 100644
--- a/lib/includes/spdylay/spdylay.h
+++ b/lib/includes/spdylay/spdylay.h
@@ -156,7 +156,7 @@ typedef enum {
   /**
    * The user callback function failed. This is a fatal error.
    */
-  SPDYLAY_ERR_CALLBACK_FAILURE = -902,
+  SPDYLAY_ERR_CALLBACK_FAILURE = -902
 } spdylay_error;
 
 typedef enum {
@@ -207,7 +207,7 @@ typedef enum {
   /**
    * The DATA frame.
    */
-  SPDYLAY_DATA = 100,
+  SPDYLAY_DATA = 100
 } spdylay_frame_type;
 
 /**
diff --git a/lib/spdylay_frame.c b/lib/spdylay_frame.c
index 8331f31..d047622 100644
--- a/lib/spdylay_frame.c
+++ b/lib/spdylay_frame.c
@@ -127,7 +127,7 @@ int spdylay_frame_count_unpack_nv_space
   size_t buflen = 0;
   size_t nvlen = 0;
   size_t off = 0;
-  int i;
+  size_t i;
   if(inlen < len_size) {
     return SPDYLAY_ERR_INVALID_FRAME;
   }
@@ -136,7 +136,7 @@ int spdylay_frame_count_unpack_nv_space
   off += len_size;
   for(i = 0; i < n; ++i) {
     uint32_t len;
-    int j;
+    size_t j;
     for(j = 0; j < 2; ++j) {
       if(inlen-off < len_size) {
         return SPDYLAY_ERR_INVALID_FRAME;
@@ -169,7 +169,8 @@ int spdylay_frame_unpack_nv(char ***nv_ptr, const uint8_t *in, size_t inlen,
                             size_t len_size)
 {
   size_t nvlen, buflen;
-  int r, i;
+  int r;
+  size_t i;
   char *buf, **index, *data;
   uint32_t n;
   r = spdylay_frame_count_unpack_nv_space(&nvlen, &buflen, in, inlen, len_size);
@@ -217,7 +218,7 @@ int spdylay_frame_unpack_nv(char ***nv_ptr, const uint8_t *in, size_t inlen,
     *index++ = val;
   }
   *index = NULL;
-  assert((char*)index-buf == (nvlen*2)*sizeof(char*));
+  assert((size_t)((char*)index - buf) == (nvlen*2)*sizeof(char*));
   *nv_ptr = (char**)buf;
   return 0;
 }
@@ -900,7 +901,8 @@ ssize_t spdylay_frame_pack_settings(uint8_t **buf_ptr, size_t *buflen_ptr,
                                     spdylay_settings *frame)
 {
   ssize_t framelen = SPDYLAY_FRAME_HEAD_LENGTH+frame->hd.length;
-  int i, r;
+  size_t i;
+  int r;
   if(frame->hd.version != SPDYLAY_PROTO_SPDY2 &&
      frame->hd.version != SPDYLAY_PROTO_SPDY3) {
     return SPDYLAY_ERR_UNSUPPORTED_VERSION;
@@ -943,7 +945,7 @@ int spdylay_frame_unpack_settings(spdylay_settings *frame,
                                   const uint8_t *head, size_t headlen,
                                   const uint8_t *payload, size_t payloadlen)
 {
-  int i;
+  size_t i;
   if(payloadlen < 4) {
     return SPDYLAY_ERR_INVALID_FRAME;
   }
@@ -962,7 +964,7 @@ int spdylay_frame_unpack_settings(spdylay_settings *frame,
   }
   if(frame->hd.version == SPDYLAY_PROTO_SPDY2) {
     for(i = 0; i < frame->niv; ++i) {
-      int off = i*8;
+      size_t off = i*8;
       /* ID is little endian. See comments in
          spdylay_frame_pack_settings(). */
       frame->iv[i].settings_id = 0;
@@ -978,7 +980,7 @@ int spdylay_frame_unpack_settings(spdylay_settings *frame,
     }
   } else {
     for(i = 0; i < frame->niv; ++i) {
-      int off = i*8;
+      size_t off = i*8;
       frame->iv[i].settings_id = spdylay_get_uint32(&payload[4+off]) &
         SPDYLAY_SETTINGS_ID_MASK;
       frame->iv[i].flags = payload[4+off];
diff --git a/lib/spdylay_helper.c b/lib/spdylay_helper.c
index 9243886..8c47f05 100644
--- a/lib/spdylay_helper.c
+++ b/lib/spdylay_helper.c
@@ -57,8 +57,9 @@ int spdylay_reserve_buffer(uint8_t **buf_ptr, size_t *buflen_ptr,
                            size_t min_length)
 {
   if(min_length > *buflen_ptr) {
+    uint8_t *temp;
     min_length = (min_length+4095)/4096*4096;
-    uint8_t *temp = malloc(min_length);
+    temp = malloc(min_length);
     if(temp == NULL) {
       return SPDYLAY_ERR_NOMEM;
     } else {
diff --git a/lib/spdylay_npn.c b/lib/spdylay_npn.c
index 73f664c..5d3473c 100644
--- a/lib/spdylay_npn.c
+++ b/lib/spdylay_npn.c
@@ -42,7 +42,7 @@ int spdylay_select_next_protocol(unsigned char **out, unsigned char *outlen,
     { (const unsigned char*)"spdy/3", 6, SPDYLAY_PROTO_SPDY3 }
   };
   for(; i < inlen; i += in[i]+1) {
-    int j;
+    unsigned int j;
     for(j = 0; j < sizeof(proto_list)/sizeof(spdylay_npn_proto); ++j) {
       if(in[i] == proto_list[j].len &&
          memcmp(&in[i+1], proto_list[j].proto, in[i]) == 0) {
diff --git a/lib/spdylay_pq.c b/lib/spdylay_pq.c
index 8422596..a85ef8c 100644
--- a/lib/spdylay_pq.c
+++ b/lib/spdylay_pq.c
@@ -91,7 +91,7 @@ static void bubble_down(spdylay_pq *pq, size_t index)
 {
   size_t lchild = index*2+1;
   size_t minindex = index;
-  int i, j;
+  size_t i, j;
   for(i = 0; i < 2; ++i) {
     j = lchild+i;
     if(j >= pq->length) {
diff --git a/lib/spdylay_queue.c b/lib/spdylay_queue.c
index d718e58..a088147 100644
--- a/lib/spdylay_queue.c
+++ b/lib/spdylay_queue.c
@@ -36,12 +36,13 @@ void spdylay_queue_free(spdylay_queue *queue)
 {
   if(!queue) {
     return;
-  }
-  spdylay_queue_cell *p = queue->front;
-  while(p) {
-    spdylay_queue_cell *next = p->next;
-    free(p);
-    p = next;
+  } else {
+    spdylay_queue_cell *p = queue->front;
+    while(p) {
+      spdylay_queue_cell *next = p->next;
+      free(p);
+      p = next;
+    }
   }
 }
 
diff --git a/lib/spdylay_session.c b/lib/spdylay_session.c
index b4d19b4..5d701f8 100644
--- a/lib/spdylay_session.c
+++ b/lib/spdylay_session.c
@@ -475,7 +475,7 @@ void spdylay_session_close_pushed_streams(spdylay_session *session,
   spdylay_stream *stream;
   stream = spdylay_session_get_stream(session, stream_id);
   if(stream) {
-    int i;
+    size_t i;
     for(i = 0; i < stream->pushed_streams_length; ++i) {
       spdylay_session_close_stream(session, stream->pushed_streams[i],
                                    status_code);
@@ -1290,7 +1290,7 @@ static ssize_t spdylay_recv(spdylay_session *session, uint8_t *buf, size_t len)
   r = session->callbacks.recv_callback
     (session, buf, len, 0, session->user_data);
   if(r > 0) {
-    if(r > len) {
+    if((size_t)r > len) {
       return SPDYLAY_ERR_CALLBACK_FAILURE;
     }
   } else if(r < 0) {
@@ -1602,7 +1602,7 @@ void spdylay_session_update_local_settings(spdylay_session *session,
                                            spdylay_settings_entry *iv,
                                            size_t niv)
 {
-  int i;
+  size_t i;
   for(i = 0; i < niv; ++i) {
     assert(iv[i].settings_id > 0 && iv[i].settings_id <= SPDYLAY_SETTINGS_MAX);
     session->local_settings[iv[i].settings_id] = iv[i].value;
@@ -1612,7 +1612,8 @@ void spdylay_session_update_local_settings(spdylay_session *session,
 int spdylay_session_on_settings_received(spdylay_session *session,
                                          spdylay_frame *frame)
 {
-  int i, check[SPDYLAY_SETTINGS_MAX+1];
+  size_t i;
+  int check[SPDYLAY_SETTINGS_MAX+1];
   if(!spdylay_session_check_version(session, frame->settings.hd.version)) {
     return 0;
   }
@@ -2011,7 +2012,7 @@ static int spdylay_session_update_recv_window_size(spdylay_session *session,
   if(stream) {
     stream->recv_window_size += delta_size;
     /* This is just a heuristics. */
-    if(stream->recv_window_size*2 >=
+    if((size_t)stream->recv_window_size*2 >=
        session->remote_settings[SPDYLAY_SETTINGS_INITIAL_WINDOW_SIZE]) {
       int r;
       r = spdylay_session_add_window_update(session, stream_id,
@@ -2267,7 +2268,7 @@ ssize_t spdylay_session_pack_data(spdylay_session *session,
      &eof, &frame->data_prd.source, session->user_data);
   if(r < 0) {
     return r;
-  } else if(datamax < r) {
+  } else if(datamax < (size_t)r) {
     return SPDYLAY_ERR_CALLBACK_FAILURE;
   }
   memset(*buf_ptr, 0, SPDYLAY_HEAD_LEN);
diff --git a/lib/spdylay_submit.c b/lib/spdylay_submit.c
index d99cf74..d58e985 100644
--- a/lib/spdylay_submit.c
+++ b/lib/spdylay_submit.c
@@ -195,7 +195,8 @@ int spdylay_submit_settings(spdylay_session *session, uint8_t flags,
   spdylay_frame *frame;
   spdylay_settings_entry *iv_copy;
   int check[SPDYLAY_SETTINGS_MAX+1];
-  int i, r;
+  size_t i;
+  int r;
   memset(check, 0, sizeof(check));
   for(i = 0; i < niv; ++i) {
     if(iv[i].settings_id > SPDYLAY_SETTINGS_MAX || iv[i].settings_id == 0 ||
diff --git a/tests/main.c b/tests/main.c
index f2b2549..924f902 100644
--- a/tests/main.c
+++ b/tests/main.c
@@ -36,12 +36,12 @@
 #include "spdylay_stream_test.h"
 #include "spdylay_npn_test.h"
 
-int init_suite1(void)
+static int init_suite1(void)
 {
   return 0;
 }
 
-int clean_suite1(void)
+static int clean_suite1(void)
 {
   return 0;
 }
diff --git a/tests/spdylay_buffer_test.c b/tests/spdylay_buffer_test.c
index 8d992b0..dc3c616 100644
--- a/tests/spdylay_buffer_test.c
+++ b/tests/spdylay_buffer_test.c
@@ -30,7 +30,7 @@
 
 #include "spdylay_buffer.h"
 
-void test_spdylay_buffer()
+void test_spdylay_buffer(void)
 {
   spdylay_buffer buffer;
   uint8_t out[1024];
diff --git a/tests/spdylay_buffer_test.h b/tests/spdylay_buffer_test.h
index 99ea485..312b404 100644
--- a/tests/spdylay_buffer_test.h
+++ b/tests/spdylay_buffer_test.h
@@ -25,6 +25,6 @@
 #ifndef SPDYLAY_BUFFER_TEST_H
 #define SPDYLAY_BUFFER_TEST_H
 
-void test_spdylay_buffer();
+void test_spdylay_buffer(void);
 
-#endif // SPDYLAY_BUFFER_TEST_H
+#endif /* SPDYLAY_BUFFER_TEST_H */
diff --git a/tests/spdylay_frame_test.c b/tests/spdylay_frame_test.c
index 251ce09..6606395 100644
--- a/tests/spdylay_frame_test.c
+++ b/tests/spdylay_frame_test.c
@@ -39,7 +39,7 @@ static const char *headers[] = {
   NULL
 };
 
-void test_spdylay_frame_unpack_nv_with(size_t len_size)
+static void test_spdylay_frame_unpack_nv_with(size_t len_size)
 {
   uint8_t out[1024];
   char **nv;
@@ -60,17 +60,17 @@ void test_spdylay_frame_unpack_nv_with(size_t len_size)
   spdylay_frame_nv_del(nv);
 }
 
-void test_spdylay_frame_unpack_nv_spdy2()
+void test_spdylay_frame_unpack_nv_spdy2(void)
 {
   test_spdylay_frame_unpack_nv_with(2);
 }
 
-void test_spdylay_frame_unpack_nv_spdy3()
+void test_spdylay_frame_unpack_nv_spdy3(void)
 {
   test_spdylay_frame_unpack_nv_with(4);
 }
 
-void test_spdylay_frame_pack_nv_duplicate_keys()
+void test_spdylay_frame_pack_nv_duplicate_keys(void)
 {
   uint8_t out[1024];
   size_t len_size = 2;
@@ -84,13 +84,16 @@ void test_spdylay_frame_pack_nv_duplicate_keys()
     NULL
   };
   char **nv = spdylay_frame_nv_norm_copy(nv_src);
+  const uint8_t *outptr;
+  int pairs, len;
   /* size_t inlen = */ spdylay_frame_pack_nv(out, nv, len_size);
-  const uint8_t *outptr = out;
-  int pairs = spdylay_get_uint16(outptr);
+  outptr = out;
+
+  pairs = spdylay_get_uint16(outptr);
   CU_ASSERT(pairs == 5);
   outptr += 2;
 
-  int len = spdylay_get_uint16(outptr);
+  len = spdylay_get_uint16(outptr);
   outptr += 2;
   CU_ASSERT(len == 6);
   CU_ASSERT(memcmp(outptr, "method", len) == 0);
@@ -154,7 +157,7 @@ void test_spdylay_frame_pack_nv_duplicate_keys()
   spdylay_frame_nv_del(nv);
 }
 
-void test_spdylay_frame_count_nv_space()
+void test_spdylay_frame_count_nv_space(void)
 {
   size_t len_size = 2;
   CU_ASSERT(74 == spdylay_frame_count_nv_space((char**)headers, len_size));
@@ -162,7 +165,7 @@ void test_spdylay_frame_count_nv_space()
   CU_ASSERT(96 == spdylay_frame_count_nv_space((char**)headers, len_size));
 }
 
-void test_spdylay_frame_count_unpack_nv_space()
+void test_spdylay_frame_count_unpack_nv_space(void)
 {
   size_t nvlen, buflen;
   uint8_t out[1024];
@@ -199,7 +202,7 @@ void test_spdylay_frame_count_unpack_nv_space()
                                                 len_size));
 }
 
-void test_spdylay_frame_pack_ping()
+void test_spdylay_frame_pack_ping(void)
 {
   spdylay_frame frame, oframe;
   uint8_t *buf = NULL;
@@ -218,7 +221,7 @@ void test_spdylay_frame_pack_ping()
   spdylay_frame_ping_free(&frame.ping);
 }
 
-void test_spdylay_frame_pack_goaway_version(uint16_t version)
+static void test_spdylay_frame_pack_goaway_version(uint16_t version)
 {
   spdylay_frame frame, oframe;
   uint8_t *buf = NULL;
@@ -248,17 +251,17 @@ void test_spdylay_frame_pack_goaway_version(uint16_t version)
   spdylay_frame_goaway_free(&frame.goaway);
 }
 
-void test_spdylay_frame_pack_goaway_spdy2()
+void test_spdylay_frame_pack_goaway_spdy2(void)
 {
   test_spdylay_frame_pack_goaway_version(SPDYLAY_PROTO_SPDY2);
 }
 
-void test_spdylay_frame_pack_goaway_spdy3()
+void test_spdylay_frame_pack_goaway_spdy3(void)
 {
   test_spdylay_frame_pack_goaway_version(SPDYLAY_PROTO_SPDY3);
 }
 
-void test_spdylay_frame_pack_syn_stream_version(uint16_t version)
+static void test_spdylay_frame_pack_syn_stream_version(uint16_t version)
 {
   spdylay_zlib deflater, inflater;
   spdylay_frame frame, oframe;
@@ -301,17 +304,17 @@ void test_spdylay_frame_pack_syn_stream_version(uint16_t version)
   spdylay_buffer_free(&inflatebuf);
 }
 
-void test_spdylay_frame_pack_syn_stream_spdy2()
+void test_spdylay_frame_pack_syn_stream_spdy2(void)
 {
   test_spdylay_frame_pack_syn_stream_version(SPDYLAY_PROTO_SPDY2);
 }
 
-void test_spdylay_frame_pack_syn_stream_spdy3()
+void test_spdylay_frame_pack_syn_stream_spdy3(void)
 {
   test_spdylay_frame_pack_syn_stream_version(SPDYLAY_PROTO_SPDY3);
 }
 
-void test_spdylay_frame_pack_syn_reply_version(uint16_t version)
+static void test_spdylay_frame_pack_syn_reply_version(uint16_t version)
 {
   spdylay_zlib deflater, inflater;
   spdylay_frame frame, oframe;
@@ -353,17 +356,17 @@ void test_spdylay_frame_pack_syn_reply_version(uint16_t version)
   spdylay_buffer_free(&inflatebuf);
 }
 
-void test_spdylay_frame_pack_syn_reply_spdy2()
+void test_spdylay_frame_pack_syn_reply_spdy2(void)
 {
   test_spdylay_frame_pack_syn_reply_version(SPDYLAY_PROTO_SPDY2);
 }
 
-void test_spdylay_frame_pack_syn_reply_spdy3()
+void test_spdylay_frame_pack_syn_reply_spdy3(void)
 {
   test_spdylay_frame_pack_syn_reply_version(SPDYLAY_PROTO_SPDY3);
 }
 
-void test_spdylay_frame_pack_headers_version(uint16_t version)
+static void test_spdylay_frame_pack_headers_version(uint16_t version)
 {
   spdylay_zlib deflater, inflater;
   spdylay_frame frame, oframe;
@@ -405,17 +408,17 @@ void test_spdylay_frame_pack_headers_version(uint16_t version)
   spdylay_buffer_free(&inflatebuf);
 }
 
-void test_spdylay_frame_pack_headers_spdy2()
+void test_spdylay_frame_pack_headers_spdy2(void)
 {
   test_spdylay_frame_pack_headers_version(SPDYLAY_PROTO_SPDY2);
 }
 
-void test_spdylay_frame_pack_headers_spdy3()
+void test_spdylay_frame_pack_headers_spdy3(void)
 {
   test_spdylay_frame_pack_headers_version(SPDYLAY_PROTO_SPDY3);
 }
 
-void test_spdylay_frame_pack_window_update()
+void test_spdylay_frame_pack_window_update(void)
 {
   spdylay_frame frame, oframe;
   uint8_t *buf = NULL;
@@ -442,7 +445,7 @@ void test_spdylay_frame_pack_window_update()
 }
 
 
-void test_spdylay_frame_pack_settings_version(uint16_t version)
+static void test_spdylay_frame_pack_settings_version(uint16_t version)
 {
   spdylay_frame frame, oframe;
   uint8_t *buf = NULL;
@@ -489,17 +492,17 @@ void test_spdylay_frame_pack_settings_version(uint16_t version)
   spdylay_frame_settings_free(&oframe.settings);
 }
 
-void test_spdylay_frame_pack_settings_spdy2()
+void test_spdylay_frame_pack_settings_spdy2(void)
 {
   test_spdylay_frame_pack_settings_version(SPDYLAY_PROTO_SPDY2);
 }
 
-void test_spdylay_frame_pack_settings_spdy3()
+void test_spdylay_frame_pack_settings_spdy3(void)
 {
   test_spdylay_frame_pack_settings_version(SPDYLAY_PROTO_SPDY3);
 }
 
-void test_spdylay_frame_nv_sort()
+void test_spdylay_frame_nv_sort(void)
 {
   char *nv[7];
   nv[0] = (char*)"version";
@@ -518,7 +521,7 @@ void test_spdylay_frame_nv_sort()
   CU_ASSERT(strcmp("HTTP/1.1", nv[5]) == 0);
 }
 
-void test_spdylay_frame_nv_downcase()
+void test_spdylay_frame_nv_downcase(void)
 {
   const char *nv_src[] = {
     "VERSION", "HTTP/1.1",
@@ -535,7 +538,7 @@ void test_spdylay_frame_nv_downcase()
   spdylay_frame_nv_del(nv);
 }
 
-void test_spdylay_frame_nv_2to3()
+void test_spdylay_frame_nv_2to3(void)
 {
   const char *nv_src[] = {
     "host", "localhost",
@@ -560,7 +563,7 @@ void test_spdylay_frame_nv_2to3()
   spdylay_frame_nv_del(nv);
 }
 
-void test_spdylay_frame_nv_3to2()
+void test_spdylay_frame_nv_3to2(void)
 {
   const char *nv_src[] = {
     ":host", "localhost",
diff --git a/tests/spdylay_frame_test.h b/tests/spdylay_frame_test.h
index a53aa4a..da8fb1f 100644
--- a/tests/spdylay_frame_test.h
+++ b/tests/spdylay_frame_test.h
@@ -25,26 +25,26 @@
 #ifndef SPDYLAY_FRAME_TEST_H
 #define SPDYLAY_FRAME_TEST_H
 
-void test_spdylay_frame_unpack_nv_spdy2();
-void test_spdylay_frame_unpack_nv_spdy3();
-void test_spdylay_frame_pack_nv_duplicate_keys();
-void test_spdylay_frame_count_nv_space();
-void test_spdylay_frame_count_unpack_nv_space();
-void test_spdylay_frame_pack_ping();
-void test_spdylay_frame_pack_goaway_spdy2();
-void test_spdylay_frame_pack_goaway_spdy3();
-void test_spdylay_frame_pack_syn_stream_spdy2();
-void test_spdylay_frame_pack_syn_stream_spdy3();
-void test_spdylay_frame_pack_syn_reply_spdy2();
-void test_spdylay_frame_pack_syn_reply_spdy3();
-void test_spdylay_frame_pack_headers_spdy2();
-void test_spdylay_frame_pack_headers_spdy3();
-void test_spdylay_frame_pack_window_update();
-void test_spdylay_frame_pack_settings_spdy2();
-void test_spdylay_frame_pack_settings_spdy3();
-void test_spdylay_frame_nv_sort();
-void test_spdylay_frame_nv_downcase();
-void test_spdylay_frame_nv_2to3();
-void test_spdylay_frame_nv_3to2();
+void test_spdylay_frame_unpack_nv_spdy2(void);
+void test_spdylay_frame_unpack_nv_spdy3(void);
+void test_spdylay_frame_pack_nv_duplicate_keys(void);
+void test_spdylay_frame_count_nv_space(void);
+void test_spdylay_frame_count_unpack_nv_space(void);
+void test_spdylay_frame_pack_ping(void);
+void test_spdylay_frame_pack_goaway_spdy2(void);
+void test_spdylay_frame_pack_goaway_spdy3(void);
+void test_spdylay_frame_pack_syn_stream_spdy2(void);
+void test_spdylay_frame_pack_syn_stream_spdy3(void);
+void test_spdylay_frame_pack_syn_reply_spdy2(void);
+void test_spdylay_frame_pack_syn_reply_spdy3(void);
+void test_spdylay_frame_pack_headers_spdy2(void);
+void test_spdylay_frame_pack_headers_spdy3(void);
+void test_spdylay_frame_pack_window_update(void);
+void test_spdylay_frame_pack_settings_spdy2(void);
+void test_spdylay_frame_pack_settings_spdy3(void);
+void test_spdylay_frame_nv_sort(void);
+void test_spdylay_frame_nv_downcase(void);
+void test_spdylay_frame_nv_2to3(void);
+void test_spdylay_frame_nv_3to2(void);
 
 #endif /* SPDYLAY_FRAME_TEST_H */
diff --git a/tests/spdylay_map_test.c b/tests/spdylay_map_test.c
index 99b2cb9..9f9f9d2 100644
--- a/tests/spdylay_map_test.c
+++ b/tests/spdylay_map_test.c
@@ -28,7 +28,7 @@
 
 #include "spdylay_map.h"
 
-void test_spdylay_map()
+void test_spdylay_map(void)
 {
   spdylay_map map;
   spdylay_map_init(&map);
diff --git a/tests/spdylay_map_test.h b/tests/spdylay_map_test.h
index 65900a9..1615ff3 100644
--- a/tests/spdylay_map_test.h
+++ b/tests/spdylay_map_test.h
@@ -25,6 +25,6 @@
 #ifndef SPDYLAY_MAP_TEST_H
 #define SPDYLAY_MAP_TEST_H
 
-void test_spdylay_map();
+void test_spdylay_map(void);
 
 #endif /* SPDYLAY_MAP_TEST_H */
diff --git a/tests/spdylay_npn_test.c b/tests/spdylay_npn_test.c
index 3b28cc3..726da03 100644
--- a/tests/spdylay_npn_test.c
+++ b/tests/spdylay_npn_test.c
@@ -22,12 +22,13 @@
  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
+#include "spdylay_npn_test.h"
 
 #include <CUnit/CUnit.h>
 #include <spdylay/spdylay.h>
 #include <string.h>
 
-static void spdy2()
+static void spdy2(void)
 {
   const unsigned char spdy[] = {
     8, 'h', 't', 't', 'p', '/', '1', '.', '1',
@@ -42,7 +43,7 @@ static void spdy2()
   CU_ASSERT(memcmp("spdy/2", out, outlen) == 0);
 }
 
-static void http11()
+static void http11(void)
 {
   const unsigned char spdy[] = {
     6, 's', 'p', 'd', 'y', '/', '4',
@@ -57,7 +58,7 @@ static void http11()
   CU_ASSERT(memcmp("http/1.1", out, outlen) == 0);
 }
 
-static void no_overlap()
+static void no_overlap(void)
 {
   const unsigned char spdy[] = {
     6, 's', 'p', 'd', 'y', '/', '4',
@@ -72,7 +73,7 @@ static void no_overlap()
   CU_ASSERT(NULL == out);
 }
 
-void test_spdylay_npn()
+void test_spdylay_npn(void)
 {
   spdy2();
   http11();
diff --git a/tests/spdylay_npn_test.h b/tests/spdylay_npn_test.h
index 59a6c45..890b7d2 100644
--- a/tests/spdylay_npn_test.h
+++ b/tests/spdylay_npn_test.h
@@ -25,6 +25,6 @@
 #ifndef SPDYLAY_NPN_TEST_H
 #define SPDYLAY_NPN_TEST_H
 
-void test_spdylay_npn();
+void test_spdylay_npn(void);
 
-#endif // SPDYLAY_NPN_TEST_H
+#endif /* SPDYLAY_NPN_TEST_H */
diff --git a/tests/spdylay_pq_test.c b/tests/spdylay_pq_test.c
index e5bfef6..978864b 100644
--- a/tests/spdylay_pq_test.c
+++ b/tests/spdylay_pq_test.c
@@ -33,7 +33,7 @@ static int pq_compar(const void *lhs, const void *rhs)
   return strcmp(lhs, rhs);
 }
 
-void test_spdylay_pq()
+void test_spdylay_pq(void)
 {
   spdylay_pq pq;
   spdylay_pq_init(&pq, pq_compar);
diff --git a/tests/spdylay_pq_test.h b/tests/spdylay_pq_test.h
index 1856c04..94b3a10 100644
--- a/tests/spdylay_pq_test.h
+++ b/tests/spdylay_pq_test.h
@@ -25,6 +25,6 @@
 #ifndef SPDYLAY_PQ_TEST_H
 #define SPDYLAY_PQ_TEST_H
 
-void test_spdylay_pq();
+void test_spdylay_pq(void);
 
 #endif /* SPDYLAY_PQ_TEST_H */
diff --git a/tests/spdylay_queue_test.c b/tests/spdylay_queue_test.c
index d46526f..772357a 100644
--- a/tests/spdylay_queue_test.c
+++ b/tests/spdylay_queue_test.c
@@ -28,7 +28,7 @@
 
 #include "spdylay_queue.h"
 
-void test_spdylay_queue()
+void test_spdylay_queue(void)
 {
   int ints[] = { 1, 2, 3, 4, 5 };
   int i;
diff --git a/tests/spdylay_queue_test.h b/tests/spdylay_queue_test.h
index 3540837..05a61c2 100644
--- a/tests/spdylay_queue_test.h
+++ b/tests/spdylay_queue_test.h
@@ -25,6 +25,6 @@
 #ifndef SPDYLAY_QUEUE_TEST_H
 #define SPDYLAY_QUEUE_TEST_H
 
-void test_spdylay_queue();
+void test_spdylay_queue(void);
 
-#endif // SPDYLAY_QUEUE_TEST_H
+#endif /* SPDYLAY_QUEUE_TEST_H */
diff --git a/tests/spdylay_session_test.c b/tests/spdylay_session_test.c
index fbe6c7a..83f060a 100644
--- a/tests/spdylay_session_test.c
+++ b/tests/spdylay_session_test.c
@@ -200,7 +200,7 @@ static spdylay_settings_entry* dup_iv(const spdylay_settings_entry *iv,
   return spdylay_frame_iv_copy(iv, niv);
 }
 
-void test_spdylay_session_recv()
+void test_spdylay_session_recv(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -238,20 +238,17 @@ void test_spdylay_session_recv()
   spdylay_frame_syn_stream_free(&frame.syn_stream);
 
   user_data.ctrl_recv_cb_called = 0;
-  while(df.seqidx < framelen) {
+  while((ssize_t)df.seqidx < framelen) {
     CU_ASSERT(0 == spdylay_session_recv(session));
   }
   CU_ASSERT(1 == user_data.ctrl_recv_cb_called);
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_add_frame()
+void test_spdylay_session_add_frame(void)
 {
   spdylay_session *session;
-  spdylay_session_callbacks callbacks = {
-    accumulator_send_callback,
-    NULL,
-  };
+  spdylay_session_callbacks callbacks;
   accumulator acc;
   my_user_data user_data;
   const char *nv[] = {
@@ -268,6 +265,8 @@ void test_spdylay_session_add_frame()
     0x80, 0x02, 0x00, 0x01
   };
   uint32_t temp32;
+  memset(&callbacks, 0, sizeof(spdylay_session_callbacks));
+  callbacks.send_callback = accumulator_send_callback;
   memset(aux_data, 0, sizeof(spdylay_syn_stream_aux_data));
   acc.length = 0;
   user_data.acc = &acc;
@@ -298,15 +297,10 @@ void test_spdylay_session_add_frame()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_recv_invalid_stream_id()
+void test_spdylay_session_recv_invalid_stream_id(void)
 {
   spdylay_session *session;
-  spdylay_session_callbacks callbacks = {
-    NULL,
-    scripted_recv_callback,
-    NULL,
-    on_invalid_ctrl_recv_callback
-  };
+  spdylay_session_callbacks callbacks;
   scripted_data_feed df;
   my_user_data user_data;
   const char *nv[] = { NULL };
@@ -314,6 +308,9 @@ void test_spdylay_session_recv_invalid_stream_id()
   size_t framedatalen = 0, nvbuflen = 0;
   ssize_t framelen;
   spdylay_frame frame;
+  memset(&callbacks, 0, sizeof(spdylay_session_callbacks));
+  callbacks.recv_callback = scripted_recv_callback;
+  callbacks.on_invalid_ctrl_recv_callback = on_invalid_ctrl_recv_callback;
 
   user_data.df = &df;
   user_data.invalid_ctrl_recv_cb_called = 0;
@@ -348,7 +345,7 @@ void test_spdylay_session_recv_invalid_stream_id()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_on_syn_stream_received()
+void test_spdylay_session_on_syn_stream_received(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -416,7 +413,7 @@ void test_spdylay_session_on_syn_stream_received()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_on_syn_stream_received_with_push()
+void test_spdylay_session_on_syn_stream_received_with_push(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -470,7 +467,7 @@ void test_spdylay_session_on_syn_stream_received_with_push()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_on_syn_reply_received()
+void test_spdylay_session_on_syn_reply_received(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -547,21 +544,18 @@ void test_spdylay_session_on_syn_reply_received()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_send_syn_stream()
+void test_spdylay_session_send_syn_stream(void)
 {
   spdylay_session *session;
-  spdylay_session_callbacks callbacks = {
-    null_send_callback,
-    NULL,
-    NULL,
-    NULL
-  };
+  spdylay_session_callbacks callbacks;
   const char *nv[] = { NULL };
   spdylay_frame *frame = malloc(sizeof(spdylay_frame));
   spdylay_stream *stream;
   spdylay_syn_stream_aux_data *aux_data =
     malloc(sizeof(spdylay_syn_stream_aux_data));
   memset(aux_data, 0, sizeof(spdylay_syn_stream_aux_data));
+  memset(&callbacks, 0, sizeof(spdylay_session_callbacks));
+  callbacks.send_callback = null_send_callback;
 
   spdylay_session_client_new(&session, SPDYLAY_PROTO_SPDY2, &callbacks, NULL);
   spdylay_frame_syn_stream_init(&frame->syn_stream, SPDYLAY_PROTO_SPDY2,
@@ -574,19 +568,17 @@ void test_spdylay_session_send_syn_stream()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_send_syn_reply()
+void test_spdylay_session_send_syn_reply(void)
 {
   spdylay_session *session;
-  spdylay_session_callbacks callbacks = {
-    null_send_callback,
-    NULL,
-    NULL,
-    NULL
-  };
+  spdylay_session_callbacks callbacks;
   const char *nv[] = { NULL };
   spdylay_frame *frame = malloc(sizeof(spdylay_frame));
   spdylay_stream *stream;
 
+  memset(&callbacks, 0, sizeof(spdylay_session_callbacks));
+  callbacks.send_callback = null_send_callback;
+
   CU_ASSERT(0 == spdylay_session_client_new(&session, SPDYLAY_PROTO_SPDY2,
                                             &callbacks, NULL));
   spdylay_session_open_stream(session, 2, SPDYLAY_CTRL_FLAG_NONE, 3,
@@ -601,21 +593,19 @@ void test_spdylay_session_send_syn_reply()
   spdylay_session_del(session);
 }
 
-void test_spdylay_submit_response()
+void test_spdylay_submit_response(void)
 {
   spdylay_session *session;
-  spdylay_session_callbacks callbacks = {
-    null_send_callback,
-    NULL,
-    NULL,
-    NULL
-  };
+  spdylay_session_callbacks callbacks;
   const char *nv[] = { "Content-Length", "1024", NULL };
   int32_t stream_id = 2;
   spdylay_data_provider data_prd;
   my_user_data ud;
   spdylay_outbound_item *item;
 
+  memset(&callbacks, 0, sizeof(spdylay_session_callbacks));
+  callbacks.send_callback = null_send_callback;
+
   data_prd.read_callback = fixed_length_data_source_read_callback;
   ud.data_source_length = 64*1024;
   CU_ASSERT(0 == spdylay_session_client_new(&session, SPDYLAY_PROTO_SPDY2,
@@ -629,7 +619,7 @@ void test_spdylay_submit_response()
   spdylay_session_del(session);
 }
 
-void test_spdylay_submit_response_with_null_data_read_callback()
+void test_spdylay_submit_response_with_null_data_read_callback(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -668,20 +658,18 @@ void test_spdylay_submit_response_with_null_data_read_callback()
   spdylay_session_del(session);
 }
 
-void test_spdylay_submit_request_with_data()
+void test_spdylay_submit_request_with_data(void)
 {
   spdylay_session *session;
-  spdylay_session_callbacks callbacks = {
-    null_send_callback,
-    NULL,
-    NULL,
-    NULL
-  };
+  spdylay_session_callbacks callbacks;
   const char *nv[] = { "Version", "HTTP/1.1", NULL };
   spdylay_data_provider data_prd;
   my_user_data ud;
   spdylay_outbound_item *item;
 
+  memset(&callbacks, 0, sizeof(spdylay_session_callbacks));
+  callbacks.send_callback = null_send_callback;
+
   data_prd.read_callback = fixed_length_data_source_read_callback;
   ud.data_source_length = 64*1024;
   CU_ASSERT(0 == spdylay_session_client_new(&session, SPDYLAY_PROTO_SPDY2,
@@ -695,7 +683,7 @@ void test_spdylay_submit_request_with_data()
   spdylay_session_del(session);
 }
 
-void test_spdylay_submit_request_with_null_data_read_callback()
+void test_spdylay_submit_request_with_null_data_read_callback(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -732,7 +720,7 @@ void test_spdylay_submit_request_with_null_data_read_callback()
   spdylay_session_del(session);
 }
 
-void test_spdylay_submit_syn_stream()
+void test_spdylay_submit_syn_stream(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -771,7 +759,7 @@ void test_spdylay_submit_syn_stream()
   spdylay_session_del(session);
 }
 
-void test_spdylay_submit_syn_reply()
+void test_spdylay_submit_syn_reply(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -810,7 +798,7 @@ void test_spdylay_submit_syn_reply()
   spdylay_session_del(session);
 }
 
-void test_spdylay_submit_headers()
+void test_spdylay_submit_headers(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -862,20 +850,18 @@ void test_spdylay_submit_headers()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_reply_fail()
+void test_spdylay_session_reply_fail(void)
 {
   spdylay_session *session;
-  spdylay_session_callbacks callbacks = {
-    fail_send_callback,
-    NULL,
-    NULL,
-    NULL
-  };
+  spdylay_session_callbacks callbacks;
   const char *nv[] = { NULL };
   int32_t stream_id = 2;
   spdylay_data_provider data_prd;
   my_user_data ud;
 
+  memset(&callbacks, 0, sizeof(spdylay_session_callbacks));
+  callbacks.send_callback = fail_send_callback;
+
   data_prd.read_callback = fixed_length_data_source_read_callback;
   ud.data_source_length = 4*1024;
   CU_ASSERT(0 == spdylay_session_client_new(&session, SPDYLAY_PROTO_SPDY2,
@@ -885,7 +871,7 @@ void test_spdylay_session_reply_fail()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_on_headers_received()
+void test_spdylay_session_on_headers_received(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -965,7 +951,7 @@ void test_spdylay_session_on_headers_received()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_on_window_update_received()
+void test_spdylay_session_on_window_update_received(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -1003,15 +989,10 @@ void test_spdylay_session_on_window_update_received()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_on_ping_received()
+void test_spdylay_session_on_ping_received(void)
 {
   spdylay_session *session;
-  spdylay_session_callbacks callbacks = {
-    NULL,
-    NULL,
-    on_ctrl_recv_callback,
-    on_invalid_ctrl_recv_callback
-  };
+  spdylay_session_callbacks callbacks;
   my_user_data user_data;
   spdylay_frame frame;
   spdylay_outbound_item *top;
@@ -1019,6 +1000,10 @@ void test_spdylay_session_on_ping_received()
   user_data.ctrl_recv_cb_called = 0;
   user_data.invalid_ctrl_recv_cb_called = 0;
 
+  memset(&callbacks, 0, sizeof(spdylay_session_callbacks));
+  callbacks.on_ctrl_recv_callback = on_ctrl_recv_callback;
+  callbacks.on_invalid_ctrl_recv_callback = on_invalid_ctrl_recv_callback;
+
   spdylay_session_client_new(&session, SPDYLAY_PROTO_SPDY2, &callbacks,
                              &user_data);
   unique_id = 2;
@@ -1040,21 +1025,20 @@ void test_spdylay_session_on_ping_received()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_on_goaway_received()
+void test_spdylay_session_on_goaway_received(void)
 {
   spdylay_session *session;
-  spdylay_session_callbacks callbacks = {
-    NULL,
-    NULL,
-    on_ctrl_recv_callback,
-    on_invalid_ctrl_recv_callback,
-  };
+  spdylay_session_callbacks callbacks;
   my_user_data user_data;
   spdylay_frame frame;
   int32_t stream_id = 1000000007;
   user_data.ctrl_recv_cb_called = 0;
   user_data.invalid_ctrl_recv_cb_called = 0;
 
+  memset(&callbacks, 0, sizeof(spdylay_session_callbacks));
+  callbacks.on_ctrl_recv_callback = on_ctrl_recv_callback;
+  callbacks.on_invalid_ctrl_recv_callback = on_invalid_ctrl_recv_callback;
+
   spdylay_session_client_new(&session, SPDYLAY_PROTO_SPDY2, &callbacks,
                              &user_data);
   spdylay_frame_goaway_init(&frame.goaway, SPDYLAY_PROTO_SPDY2, stream_id,
@@ -1068,16 +1052,17 @@ void test_spdylay_session_on_goaway_received()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_on_data_received()
+void test_spdylay_session_on_data_received(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
-  memset(&callbacks, 0, sizeof(spdylay_session_callbacks));
   my_user_data user_data;
   spdylay_outbound_item *top;
   int32_t stream_id = 2;
   spdylay_stream *stream;
 
+  memset(&callbacks, 0, sizeof(spdylay_session_callbacks));
+
   spdylay_session_client_new(&session, SPDYLAY_PROTO_SPDY2, &callbacks,
                              &user_data);
   stream = spdylay_session_open_stream(session, stream_id,
@@ -1117,7 +1102,7 @@ void test_spdylay_session_on_data_received()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_is_my_stream_id()
+void test_spdylay_session_is_my_stream_id(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -1139,7 +1124,7 @@ void test_spdylay_session_is_my_stream_id()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_on_rst_received()
+void test_spdylay_session_on_rst_received(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -1172,7 +1157,7 @@ void test_spdylay_session_on_rst_received()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_send_rst_stream()
+void test_spdylay_session_send_rst_stream(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -1206,7 +1191,7 @@ void test_spdylay_session_send_rst_stream()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_get_next_ob_item()
+void test_spdylay_session_get_next_ob_item(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -1247,7 +1232,7 @@ void test_spdylay_session_get_next_ob_item()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_pop_next_ob_item()
+void test_spdylay_session_pop_next_ob_item(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -1299,7 +1284,7 @@ void test_spdylay_session_pop_next_ob_item()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_on_request_recv_callback()
+void test_spdylay_session_on_request_recv_callback(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -1366,7 +1351,7 @@ static void stream_close_callback(spdylay_session *session, int32_t stream_id,
   CU_ASSERT(stream_data != NULL);
 }
 
-void test_spdylay_session_on_stream_close()
+void test_spdylay_session_on_stream_close(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -1390,7 +1375,7 @@ void test_spdylay_session_on_stream_close()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_max_concurrent_streams()
+void test_spdylay_session_max_concurrent_streams(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -1433,7 +1418,7 @@ static ssize_t block_count_send_callback(spdylay_session* session,
   return r;
 }
 
-void test_spdylay_session_data_backoff_by_high_pri_frame()
+void test_spdylay_session_data_backoff_by_high_pri_frame(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -1478,7 +1463,7 @@ void test_spdylay_session_data_backoff_by_high_pri_frame()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_stop_data_with_rst_stream()
+void test_spdylay_session_stop_data_with_rst_stream(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -1529,7 +1514,7 @@ void test_spdylay_session_stop_data_with_rst_stream()
  * Check that on_stream_close_callback is called when server pushed
  * SYN_STREAM have SPDYLAY_CTRL_FLAG_FIN.
  */
-void test_spdylay_session_stream_close_on_syn_stream()
+void test_spdylay_session_stream_close_on_syn_stream(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -1556,7 +1541,7 @@ void test_spdylay_session_stream_close_on_syn_stream()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_recv_invalid_frame()
+void test_spdylay_session_recv_invalid_frame(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -1614,7 +1599,7 @@ static ssize_t defer_data_source_read_callback
   return SPDYLAY_ERR_DEFERRED;
 }
 
-void test_spdylay_session_defer_data()
+void test_spdylay_session_defer_data(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -1681,7 +1666,7 @@ void test_spdylay_session_defer_data()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_flow_control()
+void test_spdylay_session_flow_control(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -1756,7 +1741,7 @@ void test_spdylay_session_flow_control()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_on_ctrl_not_send()
+void test_spdylay_session_on_ctrl_not_send(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -1881,7 +1866,7 @@ void test_spdylay_session_on_ctrl_not_send()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_on_settings_received()
+void test_spdylay_session_on_settings_received(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -1889,7 +1874,7 @@ void test_spdylay_session_on_settings_received()
   spdylay_stream *stream1, *stream2;
   spdylay_frame frame;
   const size_t niv = 5;
-  spdylay_settings_entry iv[niv];
+  spdylay_settings_entry iv[255];
 
   iv[0].settings_id = SPDYLAY_SETTINGS_MAX_CONCURRENT_STREAMS;
   iv[0].value = 1000000009;
@@ -1949,7 +1934,7 @@ void test_spdylay_session_on_settings_received()
   spdylay_session_del(session);
 }
 
-void test_spdylay_submit_settings()
+void test_spdylay_submit_settings(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
@@ -2023,7 +2008,7 @@ void test_spdylay_submit_settings()
   spdylay_session_del(session);
 }
 
-void test_spdylay_session_get_outbound_queue_size()
+void test_spdylay_session_get_outbound_queue_size(void)
 {
   spdylay_session *session;
   spdylay_session_callbacks callbacks;
diff --git a/tests/spdylay_session_test.h b/tests/spdylay_session_test.h
index d4636a2..8deeee9 100644
--- a/tests/spdylay_session_test.h
+++ b/tests/spdylay_session_test.h
@@ -25,44 +25,44 @@
 #ifndef SPDYLAY_SESSION_TEST_H
 #define SPDYLAY_SESSION_TEST_H
 
-void test_spdylay_session_recv();
-void test_spdylay_session_recv_invalid_stream_id();
-void test_spdylay_session_add_frame();
-void test_spdylay_session_on_syn_stream_received();
-void test_spdylay_session_on_syn_stream_received_with_push();
-void test_spdylay_session_on_syn_reply_received();
-void test_spdylay_session_on_window_update_received();
-void test_spdylay_session_send_syn_stream();
-void test_spdylay_session_send_syn_reply();
-void test_spdylay_submit_response();
-void test_spdylay_submit_response_with_null_data_read_callback();
-void test_spdylay_submit_request_with_data();
-void test_spdylay_submit_request_with_null_data_read_callback();
-void test_spdylay_submit_syn_stream();
-void test_spdylay_submit_syn_reply();
-void test_spdylay_submit_headers();
-void test_spdylay_session_reply_fail();
-void test_spdylay_session_on_headers_received();
-void test_spdylay_session_on_ping_received();
-void test_spdylay_session_on_goaway_received();
-void test_spdylay_session_on_data_received();
-void test_spdylay_session_on_rst_received();
-void test_spdylay_session_is_my_stream_id();
-void test_spdylay_session_send_rst_stream();
-void test_spdylay_session_get_next_ob_item();
-void test_spdylay_session_pop_next_ob_item();
-void test_spdylay_session_on_request_recv_callback();
-void test_spdylay_session_on_stream_close();
-void test_spdylay_session_max_concurrent_streams();
-void test_spdylay_session_data_backoff_by_high_pri_frame();
-void test_spdylay_session_stop_data_with_rst_stream();
-void test_spdylay_session_stream_close_on_syn_stream();
-void test_spdylay_session_recv_invalid_frame();
-void test_spdylay_session_defer_data();
-void test_spdylay_session_flow_control();
-void test_spdylay_session_on_ctrl_not_send();
-void test_spdylay_session_on_settings_received();
-void test_spdylay_submit_settings();
-void test_spdylay_session_get_outbound_queue_size();
+void test_spdylay_session_recv(void);
+void test_spdylay_session_recv_invalid_stream_id(void);
+void test_spdylay_session_add_frame(void);
+void test_spdylay_session_on_syn_stream_received(void);
+void test_spdylay_session_on_syn_stream_received_with_push(void);
+void test_spdylay_session_on_syn_reply_received(void);
+void test_spdylay_session_on_window_update_received(void);
+void test_spdylay_session_send_syn_stream(void);
+void test_spdylay_session_send_syn_reply(void);
+void test_spdylay_submit_response(void);
+void test_spdylay_submit_response_with_null_data_read_callback(void);
+void test_spdylay_submit_request_with_data(void);
+void test_spdylay_submit_request_with_null_data_read_callback(void);
+void test_spdylay_submit_syn_stream(void);
+void test_spdylay_submit_syn_reply(void);
+void test_spdylay_submit_headers(void);
+void test_spdylay_session_reply_fail(void);
+void test_spdylay_session_on_headers_received(void);
+void test_spdylay_session_on_ping_received(void);
+void test_spdylay_session_on_goaway_received(void);
+void test_spdylay_session_on_data_received(void);
+void test_spdylay_session_on_rst_received(void);
+void test_spdylay_session_is_my_stream_id(void);
+void test_spdylay_session_send_rst_stream(void);
+void test_spdylay_session_get_next_ob_item(void);
+void test_spdylay_session_pop_next_ob_item(void);
+void test_spdylay_session_on_request_recv_callback(void);
+void test_spdylay_session_on_stream_close(void);
+void test_spdylay_session_max_concurrent_streams(void);
+void test_spdylay_session_data_backoff_by_high_pri_frame(void);
+void test_spdylay_session_stop_data_with_rst_stream(void);
+void test_spdylay_session_stream_close_on_syn_stream(void);
+void test_spdylay_session_recv_invalid_frame(void);
+void test_spdylay_session_defer_data(void);
+void test_spdylay_session_flow_control(void);
+void test_spdylay_session_on_ctrl_not_send(void);
+void test_spdylay_session_on_settings_received(void);
+void test_spdylay_submit_settings(void);
+void test_spdylay_session_get_outbound_queue_size(void);
 
-#endif // SPDYLAY_SESSION_TEST_H
+#endif /* SPDYLAY_SESSION_TEST_H */
diff --git a/tests/spdylay_stream_test.c b/tests/spdylay_stream_test.c
index 76b9a26..eadb8b5 100644
--- a/tests/spdylay_stream_test.c
+++ b/tests/spdylay_stream_test.c
@@ -28,7 +28,7 @@
 
 #include "spdylay_stream.h"
 
-void test_spdylay_stream_add_pushed_stream()
+void test_spdylay_stream_add_pushed_stream(void)
 {
   spdylay_stream stream;
   int i, n;
@@ -37,7 +37,7 @@ void test_spdylay_stream_add_pushed_stream()
   n = 26;
   for(i = 2; i < n; i += 2) {
     CU_ASSERT(0 == spdylay_stream_add_pushed_stream(&stream, i));
-    CU_ASSERT(i/2 == stream.pushed_streams_length);
+    CU_ASSERT((size_t)i/2 == stream.pushed_streams_length);
   }
   for(i = 2; i < n; i += 2) {
     CU_ASSERT(i == stream.pushed_streams[i/2-1]);
diff --git a/tests/spdylay_stream_test.h b/tests/spdylay_stream_test.h
index 1326063..d60b1d0 100644
--- a/tests/spdylay_stream_test.h
+++ b/tests/spdylay_stream_test.h
@@ -25,6 +25,6 @@
 #ifndef SPDYLAY_STREAM_TEST_H
 #define SPDYLAY_STREAM_TEST_H
 
-void test_spdylay_stream_add_pushed_stream();
+void test_spdylay_stream_add_pushed_stream(void);
 
 #endif /* SPDYLAY_STREAM_TEST_H */
diff --git a/tests/spdylay_zlib_test.c b/tests/spdylay_zlib_test.c
index 5ed0231..009fc84 100644
--- a/tests/spdylay_zlib_test.c
+++ b/tests/spdylay_zlib_test.c
@@ -30,7 +30,7 @@
 
 #include "spdylay_zlib.h"
 
-void test_spdylay_zlib_with(uint16_t version)
+static void test_spdylay_zlib_with(uint16_t version)
 {
   spdylay_zlib deflater, inflater;
   const char msg[] =
@@ -70,12 +70,12 @@ void test_spdylay_zlib_with(uint16_t version)
   spdylay_buffer_free(&buf);
 }
 
-void test_spdylay_zlib_spdy2()
+void test_spdylay_zlib_spdy2(void)
 {
   test_spdylay_zlib_with(SPDYLAY_PROTO_SPDY2);
 }
 
-void test_spdylay_zlib_spdy3()
+void test_spdylay_zlib_spdy3(void)
 {
   test_spdylay_zlib_with(SPDYLAY_PROTO_SPDY3);
 }
diff --git a/tests/spdylay_zlib_test.h b/tests/spdylay_zlib_test.h
index b610663..4ae113f 100644
--- a/tests/spdylay_zlib_test.h
+++ b/tests/spdylay_zlib_test.h
@@ -25,7 +25,7 @@
 #ifndef SPDYLAY_ZLIB_TEST_H
 #define SPDYLAY_ZLIB_TEST_H
 
-void test_spdylay_zlib_spdy2();
-void test_spdylay_zlib_spdy3();
+void test_spdylay_zlib_spdy2(void);
+void test_spdylay_zlib_spdy3(void);
 
-#endif // SPDYLAY_ZLIB_TEST_H
+#endif /* SPDYLAY_ZLIB_TEST_H */