diff --git a/reactos/rules.mak b/reactos/rules.mak
index 1b4098e02ac..f6ffdf522dc 100644
--- a/reactos/rules.mak
+++ b/reactos/rules.mak
@@ -38,7 +38,7 @@ endif
 # detect Windows host environment
 ifeq ($(HOST),)
 ifeq ($(word 1,$(shell gcc -dumpmachine)),mingw32)
-HOST=mingw32-windows
+export HOST=mingw32-windows
 else
 export HOST=mingw32-linux
 endif