diff --git a/ext/gl/gstglvideomixer.c b/ext/gl/gstglvideomixer.c
index 6cb5c743bb..6a068b17c2 100644
--- a/ext/gl/gstglvideomixer.c
+++ b/ext/gl/gstglvideomixer.c
@@ -43,6 +43,7 @@
 #include "config.h"
 #endif
 
+#include <string.h>
 #include <gst/controller/gstproxycontrolbinding.h>
 #include <gst/gl/gstglfuncs.h>
 #include <gst/video/gstvideoaffinetransformationmeta.h>