diff --git a/pjsip/include/pjsip/sip_transaction.h b/pjsip/include/pjsip/sip_transaction.h
index 4a7305ec6..065b71c23 100644
--- a/pjsip/include/pjsip/sip_transaction.h
+++ b/pjsip/include/pjsip/sip_transaction.h
@@ -190,11 +190,12 @@ PJ_DECL(pj_status_t) pjsip_tsx_create_uas( pjsip_module *tsx_user,
 
 /**
  * Transmit message in tdata with this transaction. It is possible to
- * pass NULL in tdata for UAC transaction, which in this case the last message
- * or the request message which was specified in #pjsip_tsx_create_uac() 
- * will be sent.
+ * pass NULL in tdata for UAC transaction, which in this case the last 
+ * message transmitted, or the request message which was specified when
+ * calling #pjsip_tsx_create_uac(), will be sent.
  *
- * This function decrements the reference counter of the transmit buffer.
+ * This function decrements the reference counter of the transmit buffer
+ * only when it returns PJ_SUCCESS;
  *
  * @param tsx       The transaction.
  * @param tdata     The outgoing message. If NULL is specified, then the
diff --git a/pjsip/src/pjsip/sip_transaction.c b/pjsip/src/pjsip/sip_transaction.c
index d9824562d..dd6c7641f 100644
--- a/pjsip/src/pjsip/sip_transaction.c
+++ b/pjsip/src/pjsip/sip_transaction.c
@@ -1226,7 +1226,9 @@ PJ_DEF(pj_status_t) pjsip_tsx_send_msg( pjsip_transaction *tsx,
     /* Will always decrement tdata reference counter
      * (consistent with other send functions.
      */
-    pjsip_tx_data_dec_ref(tdata);
+    if (status == PJ_SUCCESS) {
+	pjsip_tx_data_dec_ref(tdata);
+    }
 
     return status;
 }