diff --git a/libavcodec/cllc.c b/libavcodec/cllc.c
index 7929996771..00b7d444dc 100644
--- a/libavcodec/cllc.c
+++ b/libavcodec/cllc.c
@@ -80,6 +80,10 @@ static int read_code_table(CLLCContext *ctx, GetBitContext *gb, VLC *vlc)
 
             count++;
         }
+        if (prefix > (65535 - 256)/2) {
+            vlc->table = NULL;
+            return AVERROR_INVALIDDATA;
+        }
 
         prefix <<= 1;
     }