diff --git a/platform/x11/os_x11.cpp b/platform/x11/os_x11.cpp
index 4c45fcfaaf5..498bebdc0e4 100644
--- a/platform/x11/os_x11.cpp
+++ b/platform/x11/os_x11.cpp
@@ -33,6 +33,7 @@
 #include "key_mapping_x11.h"
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include "print_string.h"
 #include "servers/physics/physics_server_sw.h"