diff --git a/ext/hermes/yuv2yuv.c b/ext/hermes/yuv2yuv.c
index 4499af832c..4a7560d4c6 100644
--- a/ext/hermes/yuv2yuv.c
+++ b/ext/hermes/yuv2yuv.c
@@ -21,6 +21,7 @@
 
 #include <math.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include <gst/gst.h>