diff --git a/libavcodec/wmadec.c b/libavcodec/wmadec.c
index 1573e5d783..740f8b34ea 100644
--- a/libavcodec/wmadec.c
+++ b/libavcodec/wmadec.c
@@ -768,6 +768,9 @@ static int wma_decode_superframe(AVCodecContext *avctx,
         s->last_superframe_len = 0;
         return 0;
     }
+    if (buf_size < s->block_align)
+        return 0;
+    buf_size = s->block_align;
 
     samples = data;