diff --git a/Makefile b/Makefile
index bbf3a66997..bebfbb8d60 100644
--- a/Makefile
+++ b/Makefile
@@ -134,7 +134,9 @@ OTHER_SUBDIR_CFLAGS=-I../include -I..
 
 ifeq ($(origin MENUSELECT_CFLAGS),undefined)
   MENUSELECT_CFLAGS:=$(shell grep MENUSELECT_CFLAGS $(USER_MAKEOPTS) .)
-  MENUSELECT_CFLAGS?=$(shell grep MENUSELECT_CFLAGS $(GLOBAL_MAKEOPTS) .)
+  ifeq ($(MENUSELECT_CFLAGS),)
+    MENUSELECT_CFLAGS:=$(shell grep MENUSELECT_CFLAGS $(GLOBAL_MAKEOPTS) .)
+  endif
   ifneq ($(MENUSELECT_CFLAGS),)
     MENUSELECT_CFLAGS:=$(shell echo $(MENUSELECT_CFLAGS) | cut -f2 -d'=')
   endif