diff --git a/main/rtp.c b/main/rtp.c
index 8a51050b91..bb73d253fc 100644
--- a/main/rtp.c
+++ b/main/rtp.c
@@ -1840,6 +1840,9 @@ struct ast_frame *ast_rtp_read(struct ast_rtp *rtp)
 
 		rtp->f.subclass = AST_FORMAT_T140;
 		header_end = memchr(data, ((*data) & 0x7f), rtp->f.datalen);
+		if (header_end == NULL) {
+			return &ast_null_frame;
+		}
 		header_end++;
 		
 		header_length = header_end - data;