diff --git a/builtin/difftool.c b/builtin/difftool.c
index 81d733dfdf..41cd00066c 100644
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -12,8 +12,6 @@
  * Copyright (C) 2016 Johannes Schindelin
  */
 
-#define USE_THE_REPOSITORY_VARIABLE
-
 #include "builtin.h"
 
 #include "abspath.h"