diff --git a/libavfilter/avfilter.c b/libavfilter/avfilter.c
index 2dffccab89..3f94dded2d 100644
--- a/libavfilter/avfilter.c
+++ b/libavfilter/avfilter.c
@@ -510,7 +510,7 @@ static void *filter_child_next(void *obj, void *prev)
 
 static const AVClass *filter_child_class_next(const AVClass *prev)
 {
-    AVFilter *f = NULL;
+    const AVFilter *f = NULL;
 
     /* find the filter that corresponds to prev */
     while (prev && (f = avfilter_next(f)))