diff --git a/reactos/dll/win32/user32/include/user32.h b/reactos/dll/win32/user32/include/user32.h
index 7978074ce38..5d998a469cc 100644
--- a/reactos/dll/win32/user32/include/user32.h
+++ b/reactos/dll/win32/user32/include/user32.h
@@ -21,6 +21,7 @@
 #include <windows.h>
 #include <windowsx.h>
 #include <winnls32.h>
+#include <Strsafe.h>
 #include <ndk/cmfuncs.h>
 #include <ndk/kefuncs.h>
 #include <ndk/obfuncs.h>