diff --git a/tests/failmalloc_test.c b/tests/failmalloc_test.c
index 49954e9..74f53fa 100644
--- a/tests/failmalloc_test.c
+++ b/tests/failmalloc_test.c
@@ -118,7 +118,7 @@ static ssize_t get_credential_ncerts(spdylay_session *session,
 
 static ssize_t get_credential_cert(spdylay_session *session,
                                    const spdylay_origin *origin,
-                                   size_t index,
+                                   size_t idx,
                                    uint8_t *cert, size_t certlen,
                                    void *user_data)
 {
diff --git a/tests/spdylay_frame_test.c b/tests/spdylay_frame_test.c
index 3fad076..5c85244 100644
--- a/tests/spdylay_frame_test.c
+++ b/tests/spdylay_frame_test.c
@@ -664,7 +664,7 @@ void test_spdylay_frame_nv_3to2(void)
   spdylay_frame_nv_del(nv);
 }
 
-static size_t spdylay_pack_nv(uint8_t *buf, size_t len, const char **nv,
+static size_t spdylay_pack_nv(uint8_t *buf, size_t buflen, const char **nv,
                               size_t len_size)
 {
   size_t i, n;
diff --git a/tests/spdylay_map_test.c b/tests/spdylay_map_test.c
index 9f9f9d2..f5b9714 100644
--- a/tests/spdylay_map_test.c
+++ b/tests/spdylay_map_test.c
@@ -32,17 +32,18 @@ void test_spdylay_map(void)
 {
   spdylay_map map;
   spdylay_map_init(&map);
-  CU_ASSERT(0 == spdylay_map_insert(&map, 1, "foo"));
+  CU_ASSERT(0 == spdylay_map_insert(&map, 1, (void*)"foo"));
   CU_ASSERT(strcmp("foo", spdylay_map_find(&map, 1)) == 0);
   CU_ASSERT(1 == spdylay_map_size(&map));
-  CU_ASSERT(SPDYLAY_ERR_INVALID_ARGUMENT == spdylay_map_insert(&map, 1, "FOO"));
+  CU_ASSERT(SPDYLAY_ERR_INVALID_ARGUMENT == spdylay_map_insert(&map, 1,
+                                                               (void*)"FOO"));
   CU_ASSERT(1 == spdylay_map_size(&map));
   CU_ASSERT(strcmp("foo", spdylay_map_find(&map, 1)) == 0);
-  CU_ASSERT(0 == spdylay_map_insert(&map, 2, "bar"));
+  CU_ASSERT(0 == spdylay_map_insert(&map, 2, (void*)"bar"));
   CU_ASSERT(2 == spdylay_map_size(&map));
-  CU_ASSERT(0 == spdylay_map_insert(&map, 3, "baz"));
+  CU_ASSERT(0 == spdylay_map_insert(&map, 3, (void*)"baz"));
   CU_ASSERT(3 == spdylay_map_size(&map));
-  CU_ASSERT(0 == spdylay_map_insert(&map, 4, "shrubbery"));
+  CU_ASSERT(0 == spdylay_map_insert(&map, 4, (void*)"shrubbery"));
   CU_ASSERT(4 == spdylay_map_size(&map));
   CU_ASSERT(strcmp("baz", spdylay_map_find(&map, 3)) == 0);
 
diff --git a/tests/spdylay_pq_test.c b/tests/spdylay_pq_test.c
index 978864b..b49ed05 100644
--- a/tests/spdylay_pq_test.c
+++ b/tests/spdylay_pq_test.c
@@ -39,15 +39,15 @@ void test_spdylay_pq(void)
   spdylay_pq_init(&pq, pq_compar);
   CU_ASSERT(spdylay_pq_empty(&pq));
   CU_ASSERT(0 == spdylay_pq_size(&pq));
-  CU_ASSERT(0 == spdylay_pq_push(&pq, "foo"));
+  CU_ASSERT(0 == spdylay_pq_push(&pq, (void*)"foo"));
   CU_ASSERT(0 == spdylay_pq_empty(&pq));
   CU_ASSERT(1 == spdylay_pq_size(&pq));
   CU_ASSERT(strcmp("foo", spdylay_pq_top(&pq)) == 0);
-  CU_ASSERT(0 == spdylay_pq_push(&pq, "bar"));
+  CU_ASSERT(0 == spdylay_pq_push(&pq, (void*)"bar"));
   CU_ASSERT(strcmp("bar", spdylay_pq_top(&pq)) == 0);
-  CU_ASSERT(0 == spdylay_pq_push(&pq, "baz"));
+  CU_ASSERT(0 == spdylay_pq_push(&pq, (void*)"baz"));
   CU_ASSERT(strcmp("bar", spdylay_pq_top(&pq)) == 0);
-  CU_ASSERT(0 == spdylay_pq_push(&pq, "C"));
+  CU_ASSERT(0 == spdylay_pq_push(&pq, (void*)"C"));
   CU_ASSERT(4 == spdylay_pq_size(&pq));
   CU_ASSERT(strcmp("C", spdylay_pq_top(&pq)) == 0);  
   spdylay_pq_pop(&pq);
diff --git a/tests/spdylay_session_test.c b/tests/spdylay_session_test.c
index 94f7373..0fcbf23 100644
--- a/tests/spdylay_session_test.c
+++ b/tests/spdylay_session_test.c
@@ -2140,7 +2140,7 @@ static ssize_t get_credential_ncerts(spdylay_session *session,
 
 static ssize_t get_credential_cert(spdylay_session *session,
                                    const spdylay_origin *origin,
-                                   size_t index,
+                                   size_t idx,
                                    uint8_t *cert, size_t certlen,
                                    void *user_data)
 {