diff --git a/libavcodec/vorbis.c b/libavcodec/vorbis.c
index 5ccc37a2df..cca2aa7c63 100644
--- a/libavcodec/vorbis.c
+++ b/libavcodec/vorbis.c
@@ -67,7 +67,7 @@ int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, unsigned num)
     if (bits[p] > 32)
         return AVERROR_INVALIDDATA;
     for (i = 0; i < bits[p]; ++i)
-        exit_at_level[i+1] = 1 << i;
+        exit_at_level[i+1] = 1u << i;
 
     ++p;