diff --git a/examples/SpdyServer.cc b/examples/SpdyServer.cc
index d9b8200..c8c93a9 100644
--- a/examples/SpdyServer.cc
+++ b/examples/SpdyServer.cc
@@ -367,7 +367,8 @@ ssize_t hd_recv_callback(spdylay_session *session,
 } // namespace
 
 ssize_t file_read_callback
-(spdylay_session *session, uint8_t *buf, size_t length, int *eof,
+(spdylay_session *session, int32_t stream_id,
+ uint8_t *buf, size_t length, int *eof,
  spdylay_data_source *source, void *user_data)
 {
   int fd = source->fd;
diff --git a/examples/SpdyServer.h b/examples/SpdyServer.h
index 1512c35..b76dd33 100644
--- a/examples/SpdyServer.h
+++ b/examples/SpdyServer.h
@@ -152,7 +152,8 @@ void htdocs_on_request_recv_callback
 (spdylay_session *session, int32_t stream_id, void *user_data);
 
 ssize_t file_read_callback
-(spdylay_session *session, uint8_t *buf, size_t length, int *eof,
+(spdylay_session *session, int32_t stream_id,
+ uint8_t *buf, size_t length, int *eof,
  spdylay_data_source *source, void *user_data);
 
 } // namespace spdylay
diff --git a/examples/spdy.h b/examples/spdy.h
index ea883d7..ba3782c 100644
--- a/examples/spdy.h
+++ b/examples/spdy.h
@@ -135,7 +135,8 @@ private:
 };
 
 ssize_t string_read_callback
-(spdylay_session *session, uint8_t *buf, size_t length, int *eof,
+(spdylay_session *session, int32_t stream_id,
+ uint8_t *buf, size_t length, int *eof,
  spdylay_data_source *source, void *user_data)
 {
   std::pair<std::string, size_t>& body_pair =
diff --git a/lib/includes/spdylay/spdylay.h b/lib/includes/spdylay/spdylay.h
index 05a70bc..fc9db3d 100644
--- a/lib/includes/spdylay/spdylay.h
+++ b/lib/includes/spdylay/spdylay.h
@@ -182,20 +182,22 @@ typedef union {
 
 /*
  * Callback function invoked when the library wants to read data from
- * |source|. The implementation of this function must read at most
- * |length| bytes of data from |source| (or possibly other places) and
- * store them in |buf| and return number of data stored in |buf|. If
- * EOF is reached, set |*eof| to 1.  If the application wants to
- * postpone DATA frames, (e.g., asynchronous I/O, or reading data
- * blocks for long time), it is achieved by returning
- * SPDYLAY_ERR_DEFERRED without reading any data in this invocation.
- * The library removes DATA frame from outgoing queue temporarily.  To
- * move back deferred DATA frame to outgoing queue, call
- * spdylay_session_resume_data().  In case of error, return
- * SPDYLAY_ERR_CALLBACK_FAILURE, which leads to session failure.
+ * |source|. The read data is sent in the stream |stream_id|. The
+ * implementation of this function must read at most |length| bytes of
+ * data from |source| (or possibly other places) and store them in
+ * |buf| and return number of data stored in |buf|. If EOF is reached,
+ * set |*eof| to 1.  If the application wants to postpone DATA frames,
+ * (e.g., asynchronous I/O, or reading data blocks for long time), it
+ * is achieved by returning SPDYLAY_ERR_DEFERRED without reading any
+ * data in this invocation.  The library removes DATA frame from
+ * outgoing queue temporarily.  To move back deferred DATA frame to
+ * outgoing queue, call spdylay_session_resume_data().  In case of
+ * error, return SPDYLAY_ERR_CALLBACK_FAILURE, which leads to session
+ * failure.
  */
 typedef ssize_t (*spdylay_data_source_read_callback)
-(spdylay_session *session, uint8_t *buf, size_t length, int *eof,
+(spdylay_session *session, int32_t stream_id,
+ uint8_t *buf, size_t length, int *eof,
  spdylay_data_source *source, void *user_data);
 
 typedef struct {
diff --git a/lib/spdylay_session.c b/lib/spdylay_session.c
index ee61f83..ec6fcf9 100644
--- a/lib/spdylay_session.c
+++ b/lib/spdylay_session.c
@@ -1686,7 +1686,8 @@ ssize_t spdylay_session_pack_data_overwrite(spdylay_session *session,
   int eof = 0;
   uint8_t flags = 0;
   r = frame->data_prd.read_callback
-    (session, buf+8, len-8, &eof, &frame->data_prd.source, session->user_data);
+    (session, frame->stream_id, buf+8, len-8, &eof, &frame->data_prd.source,
+     session->user_data);
   if(r < 0) {
     return r;
   } else if(len < r) {
diff --git a/tests/spdylay_session_test.c b/tests/spdylay_session_test.c
index d0a18bc..50524ee 100644
--- a/tests/spdylay_session_test.c
+++ b/tests/spdylay_session_test.c
@@ -138,7 +138,8 @@ static void on_ctrl_send_callback(spdylay_session *session,
 }
 
 static ssize_t fixed_length_data_source_read_callback
-(spdylay_session *session, uint8_t *buf, size_t len, int *eof,
+(spdylay_session *session, int32_t stream_id,
+ uint8_t *buf, size_t len, int *eof,
  spdylay_data_source *source, void *user_data)
 {
   my_user_data *ud = (my_user_data*)user_data;
@@ -1274,7 +1275,8 @@ void test_spdylay_session_recv_invalid_frame()
 }
 
 static ssize_t defer_data_source_read_callback
-(spdylay_session *session, uint8_t *buf, size_t len, int *eof,
+(spdylay_session *session, int32_t stream_id,
+ uint8_t *buf, size_t len, int *eof,
  spdylay_data_source *source, void *user_data)
 {
   return SPDYLAY_ERR_DEFERRED;