diff --git a/libavcodec/aacdec.c b/libavcodec/aacdec.c
index af9187924d..f58e052257 100644
--- a/libavcodec/aacdec.c
+++ b/libavcodec/aacdec.c
@@ -781,7 +781,7 @@ static int decode_audio_specific_config(AACContext *ac,
  *
  * @return  Returns a 32-bit pseudorandom integer
  */
-static av_always_inline int lcg_random(int previous_val)
+static av_always_inline int lcg_random(unsigned previous_val)
 {
     return previous_val * 1664525 + 1013904223;
 }