diff --git a/libavcodec/rv34.c b/libavcodec/rv34.c
index 99e580a09a..6cd42e585b 100644
--- a/libavcodec/rv34.c
+++ b/libavcodec/rv34.c
@@ -96,6 +96,8 @@ static void rv34_gen_vlc(const uint8_t *bits, int size, VLC *vlc, const uint8_t
     uint16_t cw[MAX_VLC_SIZE];
     int maxbits;
 
+    av_assert1(size > 0);
+
     for (int i = 0; i < size; i++)
         counts[bits[i]]++;