diff --git a/lib/spdylay_submit.c b/lib/spdylay_submit.c
index 86245a0..2b15681 100644
--- a/lib/spdylay_submit.c
+++ b/lib/spdylay_submit.c
@@ -124,7 +124,7 @@ int spdylay_submit_request(spdylay_session *session, uint8_t pri,
   if(pri > 3) {
     return SPDYLAY_ERR_INVALID_ARGUMENT;
   }
-  if(data_prd) {
+  if(data_prd != NULL && data_prd->read_callback != NULL) {
     data_prd_copy = malloc(sizeof(spdylay_data_provider));
     if(data_prd_copy == NULL) {
       return SPDYLAY_ERR_NOMEM;