diff --git a/gnu/lib/Makefile b/gnu/lib/Makefile
index 2791b569896..cfb69a841ac 100644
--- a/gnu/lib/Makefile
+++ b/gnu/lib/Makefile
@@ -4,7 +4,6 @@
 
 SUBDIR=			csu
 SUBDIR+=		libgcc
-SUBDIR+=		libregex
 
 SUBDIR.${MK_DIALOG}+=	libdialog
 SUBDIR.${MK_GCC}+=	libgcov libgomp
@@ -15,6 +14,11 @@ SUBDIR.${MK_TESTS}+=	tests
 SUBDIR+=	libreadline
 .endif
 
+.if ${MK_GNU_DIFF} != "no" || ${MK_GNU_GREP} != "no" || \
+    ${GNU_GREP_COMPAT} != "no" || ${MK_GDB} != "no"
+SUBDIR+=		libregex
+.endif
+
 # libsupc++ uses libstdc++ headers, although 'make includes' should
 # have taken care of that already.
 .if ${MK_GNUCXX} != "no"