diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index 62e4940dc126e325285f400ac37ab2b7029b7925..86d453bba7835bedcffbbbaf4f6f37d34fb8bd7c 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -4554,7 +4554,7 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size,
                 h->workaround_bugs |= FF_BUG_TRUNCATED;
 
             if (!(h->workaround_bugs & FF_BUG_TRUNCATED))
-                while (ptr[dst_length - 1] == 0 && dst_length > 0)
+                while (dst_length > 0 && ptr[dst_length - 1] == 0)
                     dst_length--;
             bit_length = !dst_length ? 0
                                      : (8 * dst_length -