diff --git a/nt/makefile.def b/nt/makefile.def
index 4e28b0beb3d..fdfa6029653 100644
--- a/nt/makefile.def
+++ b/nt/makefile.def
@@ -142,9 +142,6 @@ CFLAGS          = $(CFLAGS_COMMON) -D_CRTAPI1=_cdecl
 !else
 CFLAGS          = $(CFLAGS_COMMON) -D_CRTAPI1=_cdecl
 !endif
-!ifdef NTGUI
-CFLAGS          = $(CFLAGS) -DHAVE_NTGUI=1
-!endif
 
 !ifdef BUILD_TYPE
 OBJDIR          = obj-$(BUILD_TYPE)