diff --git a/lib/includes/spdylay/spdylay.h b/lib/includes/spdylay/spdylay.h
index c3edd082..aa5c86fd 100644
--- a/lib/includes/spdylay/spdylay.h
+++ b/lib/includes/spdylay/spdylay.h
@@ -394,9 +394,10 @@ void* spdylay_session_get_stream_user_data(spdylay_session *session,
                                            int32_t stream_id);
 
 /*
- * Submits SYN_STREAM frame. |pri| is priority of this request and it
- * must be in the range of [0, 3]. 0 means the higest priority. |nv|
- * must include following name/value pairs:
+ * Submits SYN_STREAM frame and optionally one or more DATA
+ * frames. |pri| is priority of this request and it must be in the
+ * range of [0, 3]. 0 means the higest priority. |nv| must include
+ * following name/value pairs:
  *
  * "method": HTTP method (e.g., "GET" or "POST")
  * "scheme": URI scheme (e.g., "https")
@@ -405,7 +406,8 @@ void* spdylay_session_get_stream_user_data(spdylay_session *session,
  *
  * "host" name/value pair is also required by some hosts.
  *
- * This function creates copies of all name/value pairs in |nv|.
+ * This function creates copies of all name/value pairs in |nv|.  It
+ * also lower-cases all names in |nv|.
  *
  * If |data_prd| is not NULL, it provides data which will be sent in
  * subsequent DATA frames. In this case, "POST" must be specified with
@@ -426,14 +428,17 @@ int spdylay_submit_request(spdylay_session *session, uint8_t pri,
                            void *stream_user_data);
 
 /*
- * Submits SYN_REPLY frame against stream |stream_id|. |nv| must
- * include following name/value pairs:
+ * Submits SYN_REPLY frame and optionally one or more DATA frames
+ * against stream |stream_id|. |nv| must include following name/value
+ * pairs:
  *
  * "status": HTTP status code (e.g., "200" or "200 OK")
  * "version": HTTP response version (e.g., "HTTP/1.1")
  *
- * This function creates copies of all name/value pairs in |nv|. If
- * |data_prd| is not NULL, it provides data which will be sent in
+ * This function creates copies of all name/value pairs in |nv|.  It
+ * also lower-cases all names in |nv|.
+ *
+ * If |data_prd| is not NULL, it provides data which will be sent in
  * subsequent DATA frames. If |data_prd| is NULL, SYN_REPLY will have
  * FLAG_FIN.
  *
diff --git a/lib/spdylay_frame.c b/lib/spdylay_frame.c
index f5972f0e..567e54e1 100644
--- a/lib/spdylay_frame.c
+++ b/lib/spdylay_frame.c
@@ -315,6 +315,18 @@ void spdylay_frame_nv_sort(char **nv)
   qsort(nv, n/2, 2*sizeof(char*), spdylay_string_compar);
 }
 
+void spdylay_frame_nv_downcase(char **nv)
+{
+  int i, j;
+  for(i = 0; nv[i]; i += 2) {
+    for(j = 0; nv[i][j] != '\0'; ++j) {
+      if('A' <= nv[i][j] && nv[i][j] <= 'Z') {
+        nv[i][j] += 'a'-'A';
+      }
+    }
+  }
+}
+
 void spdylay_frame_syn_stream_init(spdylay_syn_stream *frame, uint8_t flags,
                                    int32_t stream_id, int32_t assoc_stream_id,
                                    uint8_t pri, char **nv)
diff --git a/lib/spdylay_frame.h b/lib/spdylay_frame.h
index a880a601..fcdcbe68 100644
--- a/lib/spdylay_frame.h
+++ b/lib/spdylay_frame.h
@@ -293,6 +293,11 @@ char** spdylay_frame_nv_copy(const char **nv);
  */
 void spdylay_frame_nv_sort(char **nv);
 
+/*
+ * Makes names in |nv| lower cased.
+ */
+void spdylay_frame_nv_downcase(char **nv);
+
 /*
  * Makes copy of |iv| and return the copy. The |niv| is the number of
  * entries in |iv|. This function returns the pointer to the copy if
diff --git a/lib/spdylay_submit.c b/lib/spdylay_submit.c
index c083c024..86245a09 100644
--- a/lib/spdylay_submit.c
+++ b/lib/spdylay_submit.c
@@ -71,6 +71,7 @@ int spdylay_submit_response(spdylay_session *session,
     free(data_prd_copy);
     return SPDYLAY_ERR_NOMEM;
   }
+  spdylay_frame_nv_downcase(nv_copy);
   spdylay_frame_nv_sort(nv_copy);
   if(data_prd == NULL) {
     flags |= SPDYLAY_FLAG_FIN;
@@ -151,6 +152,7 @@ int spdylay_submit_request(spdylay_session *session, uint8_t pri,
     free(data_prd_copy);
     return SPDYLAY_ERR_NOMEM;
   }
+  spdylay_frame_nv_downcase(nv_copy);
   spdylay_frame_nv_sort(nv_copy);
   if(data_prd == NULL) {
     flags |= SPDYLAY_FLAG_FIN;
diff --git a/tests/main.c b/tests/main.c
index 1a1892d7..f144a84f 100644
--- a/tests/main.c
+++ b/tests/main.c
@@ -132,6 +132,8 @@ int main(int argc, char* argv[])
       !CU_add_test(pSuite, "frame_pack_settings",
                    test_spdylay_frame_pack_settings) ||
       !CU_add_test(pSuite, "frame_nv_sort", test_spdylay_frame_nv_sort) ||
+      !CU_add_test(pSuite, "frame_nv_downcase",
+                   test_spdylay_frame_nv_downcase) ||
       !CU_add_test(pSuite, "stream_add_pushed_stream",
                    test_spdylay_stream_add_pushed_stream)) {
      CU_cleanup_registry();
diff --git a/tests/spdylay_frame_test.c b/tests/spdylay_frame_test.c
index 9f32268d..73a22e95 100644
--- a/tests/spdylay_frame_test.c
+++ b/tests/spdylay_frame_test.c
@@ -230,3 +230,20 @@ void test_spdylay_frame_nv_sort()
   CU_ASSERT(strcmp("version", nv[4]) == 0);
   CU_ASSERT(strcmp("HTTP/1.1", nv[5]) == 0);
 }
+
+void test_spdylay_frame_nv_downcase()
+{
+  const char *nv_src[] = {
+    "VERSION", "HTTP/1.1",
+    "Content-Length", "1000000007",
+    NULL
+  };
+  char **nv;
+  nv = spdylay_frame_nv_copy(nv_src);
+  spdylay_frame_nv_downcase(nv);
+  CU_ASSERT(0 == strcmp("version", nv[0]));
+  CU_ASSERT(0 == strcmp("HTTP/1.1", nv[1]));
+  CU_ASSERT(0 == strcmp("content-length", nv[2]));
+  CU_ASSERT(0 == strcmp("1000000007", nv[3]));
+  spdylay_frame_nv_del(nv);
+}
diff --git a/tests/spdylay_frame_test.h b/tests/spdylay_frame_test.h
index 26c35daa..6484e565 100644
--- a/tests/spdylay_frame_test.h
+++ b/tests/spdylay_frame_test.h
@@ -33,5 +33,6 @@ void test_spdylay_frame_pack_goaway();
 void test_spdylay_frame_pack_headers();
 void test_spdylay_frame_pack_settings();
 void test_spdylay_frame_nv_sort();
+void test_spdylay_frame_nv_downcase();
 
 #endif /* SPDYLAY_FRAME_TEST_H */
diff --git a/tests/spdylay_session_test.c b/tests/spdylay_session_test.c
index 331847f4..f7bc8fe3 100644
--- a/tests/spdylay_session_test.c
+++ b/tests/spdylay_session_test.c
@@ -527,10 +527,11 @@ void test_spdylay_submit_response()
     NULL,
     NULL
   };
-  const char *nv[] = { NULL };
+  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;
 
   data_prd.read_callback = fixed_length_data_source_read_callback;
   ud.data_source_length = 64*1024;
@@ -538,6 +539,8 @@ void test_spdylay_submit_response()
   spdylay_session_open_stream(session, stream_id, SPDYLAY_FLAG_NONE, 3,
                               SPDYLAY_STREAM_OPENING, NULL);
   CU_ASSERT(0 == spdylay_submit_response(session, stream_id, nv, &data_prd));
+  item = spdylay_session_get_next_ob_item(session);
+  CU_ASSERT(0 == strcmp("content-length", item->frame->syn_reply.nv[0]));
   CU_ASSERT(0 == spdylay_session_send(session));
   spdylay_session_del(session);
 }
@@ -551,14 +554,17 @@ void test_spdylay_submit_request_with_data()
     NULL,
     NULL
   };
-  const char *nv[] = { NULL };
+  const char *nv[] = { "Version", "HTTP/1.1", NULL };
   spdylay_data_provider data_prd;
   my_user_data ud;
+  spdylay_outbound_item *item;
 
   data_prd.read_callback = fixed_length_data_source_read_callback;
   ud.data_source_length = 64*1024;
   CU_ASSERT(0 == spdylay_session_client_new(&session, &callbacks, &ud));
   CU_ASSERT(0 == spdylay_submit_request(session, 3, nv, &data_prd, NULL));
+  item = spdylay_session_get_next_ob_item(session);
+  CU_ASSERT(0 == strcmp("version", item->frame->syn_stream.nv[0]));
   CU_ASSERT(0 == spdylay_session_send(session));
   CU_ASSERT(0 == ud.data_source_length);