diff --git a/libavcodec/mem.c b/libavcodec/mem.c
index 2f972b7c59..d24da6a15d 100644
--- a/libavcodec/mem.c
+++ b/libavcodec/mem.c
@@ -117,7 +117,11 @@ void *av_realloc(void *ptr, unsigned int size)
 #endif
 }
 
-/* NOTE: ptr = NULL is explicetly allowed */
+/**
+ * Free memory which has been allocated with av_malloc(z)() or av_realloc().
+ * NOTE: ptr = NULL is explicetly allowed 
+ * Note2: it is recommanded that you use av_freep() instead
+ */
 void av_free(void *ptr)
 {
     /* XXX: this test should not be needed on most libcs */