diff --git a/reactos/subsys/win32k/objects/line.c b/reactos/subsys/win32k/objects/line.c
index 3336cbf648d..a71e2044af7 100644
--- a/reactos/subsys/win32k/objects/line.c
+++ b/reactos/subsys/win32k/objects/line.c
@@ -2,6 +2,7 @@
 
 #undef WIN32_LEAN_AND_MEAN
 #include <windows.h>
+#include <internal/safe.h>
 #include <ddk/ntddk.h>
 #include <win32k/dc.h>
 #include <win32k/line.h>