diff --git a/reactos/subsystems/win32/win32k/pch.h b/reactos/subsystems/win32/win32k/pch.h
index 479f00a195e..b703d6b868b 100644
--- a/reactos/subsystems/win32/win32k/pch.h
+++ b/reactos/subsystems/win32/win32k/pch.h
@@ -18,6 +18,7 @@
 #include <ntifs.h>
 #include <tvout.h>
 #include <ntndk.h>
+#include <ntstrsafe.h>
 
 /* Win32 Headers */
 /* FIXME: Defines in winbase.h that we need... */