diff --git a/libavformat/aacdec.c b/libavformat/aacdec.c
index e165959dab..7c17dd05fa 100644
--- a/libavformat/aacdec.c
+++ b/libavformat/aacdec.c
@@ -31,10 +31,10 @@ static int adts_aac_probe(AVProbeData *p)
 {
     int max_frames = 0, first_frames = 0;
     int fsize, frames;
-    uint8_t *buf0 = p->buf;
-    uint8_t *buf2;
-    uint8_t *buf;
-    uint8_t *end = buf0 + p->buf_size - 7;
+    const uint8_t *buf0 = p->buf;
+    const uint8_t *buf2;
+    const uint8_t *buf;
+    const uint8_t *end = buf0 + p->buf_size - 7;
 
     buf = buf0;