diff --git a/gnu/lib/Makefile b/gnu/lib/Makefile
index cfb69a841ac..0e17c229ed2 100644
--- a/gnu/lib/Makefile
+++ b/gnu/lib/Makefile
@@ -15,7 +15,7 @@ SUBDIR+=	libreadline
 .endif
 
 .if ${MK_GNU_DIFF} != "no" || ${MK_GNU_GREP} != "no" || \
-    ${GNU_GREP_COMPAT} != "no" || ${MK_GDB} != "no"
+    ${MK_GNU_GREP_COMPAT} != "no" || ${MK_GDB} != "no"
 SUBDIR+=		libregex
 .endif