diff --git a/libavcodec/bitstream.h b/libavcodec/bitstream.h
index 3670285904..263fe9aa5a 100644
--- a/libavcodec/bitstream.h
+++ b/libavcodec/bitstream.h
@@ -337,6 +337,7 @@ static inline void skip_put_bytes(PutBitContext *s, int n){
 /**
  * Skips the given number of bits.
  * Must only be used if the actual values in the bitstream do not matter.
+ * If \p n is 0 the behavior is undefined.
  */
 static inline void skip_put_bits(PutBitContext *s, int n){
 #ifdef ALT_BITSTREAM_WRITER