diff --git a/src/parser_h264.c b/src/parser_h264.c
index 7f31f236..8b17fb82 100644
--- a/src/parser_h264.c
+++ b/src/parser_h264.c
@@ -413,7 +413,7 @@ h264_decode_slice_header(th_stream_t *st, bitstream_t *bs, int *pkttype,
     int w = p->sps[sps_id].aspect_num * st->st_width;
     int h = p->sps[sps_id].aspect_den * st->st_height;
 
-    if(w & h) { 
+    if(w && h) { 
       int d = gcd(w, h);
       st->st_aspect_num = w / d;
       st->st_aspect_den = h / d;