diff --git a/lib/spdylay_session.c b/lib/spdylay_session.c
index ee829294..7c5f6886 100644
--- a/lib/spdylay_session.c
+++ b/lib/spdylay_session.c
@@ -1529,6 +1529,7 @@ int spdylay_session_on_syn_reply_received(spdylay_session *session,
 {
   int r = 0;
   int valid = 0;
+  int status_code = SPDYLAY_PROTOCOL_ERROR;
   spdylay_stream *stream;
   if(!spdylay_session_check_version(session, frame->syn_reply.hd.version)) {
     return 0;
@@ -1554,13 +1555,21 @@ int spdylay_session_on_syn_reply_received(spdylay_session *session,
            that we queued RST_STREAM but it has not been sent. It will
            eventually sent, so we just ignore this frame. */
         valid = 1;
+      } else {
+        if(session->version == SPDYLAY_PROTO_SPDY3) {
+          /* SPDY/3 spec says if multiple SYN_REPLY frames for the
+             same active stream ID are received, the receiver must
+             issue a stream error with the status code
+             STREAM_IN_USE. */
+          status_code = SPDYLAY_STREAM_IN_USE;
+        }
       }
     }
   }
   if(!valid) {
     r = spdylay_session_handle_invalid_stream
       (session, frame->syn_reply.stream_id, SPDYLAY_SYN_REPLY, frame,
-       SPDYLAY_PROTOCOL_ERROR);
+       status_code);
   }
   return r;
 }
diff --git a/tests/spdylay_session_test.c b/tests/spdylay_session_test.c
index 4d99dd2f..a45a2997 100644
--- a/tests/spdylay_session_test.c
+++ b/tests/spdylay_session_test.c
@@ -473,20 +473,19 @@ void test_spdylay_session_on_syn_stream_received_with_push()
 void test_spdylay_session_on_syn_reply_received()
 {
   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;
   const char *nv[] = { NULL };
   const char *upcase_nv[] = { "version", "http/1.1", "methoD", "get", NULL };
   spdylay_frame frame;
   spdylay_stream *stream;
+  spdylay_outbound_item *item;
   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_session_open_stream(session, 1, SPDYLAY_CTRL_FLAG_NONE, 0,
@@ -527,6 +526,25 @@ void test_spdylay_session_on_syn_reply_received()
   spdylay_frame_syn_reply_free(&frame.syn_reply);
 
   spdylay_session_del(session);
+
+  spdylay_session_client_new(&session, SPDYLAY_PROTO_SPDY3, &callbacks,
+                             &user_data);
+
+  /* Multiple SYN_REPLY frames for the same active stream ID */
+  spdylay_session_open_stream(session, 1, SPDYLAY_CTRL_FLAG_NONE, 0,
+                              SPDYLAY_STREAM_OPENED, NULL);
+  spdylay_frame_syn_reply_init(&frame.syn_reply, SPDYLAY_PROTO_SPDY3,
+                               SPDYLAY_CTRL_FLAG_NONE, 1, dup_nv(nv));
+  user_data.invalid_ctrl_recv_cb_called = 0;
+  CU_ASSERT(0 == spdylay_session_on_syn_reply_received(session, &frame));
+  CU_ASSERT(1 == user_data.invalid_ctrl_recv_cb_called);
+  item = spdylay_session_get_next_ob_item(session);
+  CU_ASSERT(SPDYLAY_RST_STREAM == item->frame_type);
+  CU_ASSERT(SPDYLAY_STREAM_IN_USE == item->frame->rst_stream.status_code);
+
+  spdylay_frame_syn_reply_free(&frame.syn_reply);
+
+  spdylay_session_del(session);
 }
 
 void test_spdylay_session_send_syn_stream()