diff --git a/reactos/drivers/directx/dxapi/dxapi_driver.h b/reactos/drivers/directx/dxapi/dxapi_driver.h
index fa6a6fec54a..322d6d1d67f 100644
--- a/reactos/drivers/directx/dxapi/dxapi_driver.h
+++ b/reactos/drivers/directx/dxapi/dxapi_driver.h
@@ -10,6 +10,7 @@
 #include <windef.h>
 #include <winerror.h>
 #include <wingdi.h>
+#define NT_BUILD_ENVIRONMENT
 #include <winddi.h>
 #include <prntfont.h>
 #include <dde.h>
diff --git a/reactos/drivers/directx/dxg/dxg_int.h b/reactos/drivers/directx/dxg/dxg_int.h
index 606a9123e4d..0440eaaaec5 100644
--- a/reactos/drivers/directx/dxg/dxg_int.h
+++ b/reactos/drivers/directx/dxg/dxg_int.h
@@ -11,6 +11,7 @@
 #define STARTF_USESIZE 2
 #define STARTF_USEPOSITION 4
 #define INTERNAL_CALL NTAPI
+#define NT_BUILD_ENVIRONMENT
 
 #include <stdarg.h>
 #include <windef.h>