diff --git a/libavformat/omadec.c b/libavformat/omadec.c
index e49178290e..274112e5af 100644
--- a/libavformat/omadec.c
+++ b/libavformat/omadec.c
@@ -172,7 +172,11 @@ static int nprobe(AVFormatContext *s, uint8_t *enc_header, unsigned size,
     taglen  = AV_RB32(&enc_header[pos + 32]);
     datalen = AV_RB32(&enc_header[pos + 36]) >> 4;
 
-    pos += 44 + taglen;
+    pos += 44;
+    if (size - pos < taglen)
+        return -1;
+
+    pos += taglen;
 
     if (datalen << 4 > size - pos)
         return -1;