diff --git a/makefile b/makefile
index 050eaf8..2bb8132 100644
--- a/makefile
+++ b/makefile
@@ -5,8 +5,8 @@
 
 NAME := gtklock
 
-PREFIX ?= /usr/local
-INSTALL ?= install
+PREFIX = /usr/local
+INSTALL = install
 
 include util/version.mk