diff --git a/reactos/tools/unicode/unicode.mak b/reactos/tools/unicode/unicode.mak
index b88fc679747..5d5334cdc04 100644
--- a/reactos/tools/unicode/unicode.mak
+++ b/reactos/tools/unicode/unicode.mak
@@ -97,7 +97,7 @@ UNICODE_OBJECTS = \
 UNICODE_HOST_CFLAGS = \
 	-D__USE_W32API -DWINVER=0x501 -DWINE_UNICODE_API= \
 	-Dwchar_t="unsigned short" -D_WCHAR_T_DEFINED \
-	-I$(UNICODE_BASE) -Iinclude/wine
+	-I$(UNICODE_BASE) -Iinclude/wine -Iw32api/include
 
 .PHONY: unicode
 unicode: $(UNICODE_TARGET)