diff --git a/libavcodec/tiff.c b/libavcodec/tiff.c
index 1b934457b5..19301d9e49 100644
--- a/libavcodec/tiff.c
+++ b/libavcodec/tiff.c
@@ -176,7 +176,7 @@ static int cmp_id_key(const void *id, const void *k)
 
 static const char *search_keyval(const TiffGeoTagKeyName *keys, int n, int id)
 {
-    TiffGeoTagKeyName *r = bsearch(&id, keys, n, sizeof(keys[0]), cmp_id_key);
+    const TiffGeoTagKeyName *r = bsearch(&id, keys, n, sizeof(keys[0]), cmp_id_key);
     if(r)
         return r->name;