diff --git a/doc/examples/filter_audio.c b/doc/examples/filter_audio.c
index 71f985ee13af3431503fb911b23b5468a8e4ddea..60fe107dda486cd677e1a7d53726fa2e12b74084 100644
--- a/doc/examples/filter_audio.c
+++ b/doc/examples/filter_audio.c
@@ -45,6 +45,7 @@
 
 #include "libavutil/channel_layout.h"
 #include "libavutil/md5.h"
+#include "libavutil/mem.h"
 #include "libavutil/opt.h"
 #include "libavutil/samplefmt.h"