diff --git a/channels/chan_iax2.c b/channels/chan_iax2.c
index 08b64d5d27..e9cf20e5f3 100644
--- a/channels/chan_iax2.c
+++ b/channels/chan_iax2.c
@@ -6819,6 +6819,7 @@ static int socket_process(struct iax2_thread *thread)
 					return 1;
 				}
 				f.data = NULL;
+				f.datalen = 0;
 			} else
 				f.data = thread->buf + sizeof(*fh);
 		} else {