diff --git a/sys/Makefile b/sys/Makefile
index fcb7e0a7c779..8af56b8a40ae 100644
--- a/sys/Makefile
+++ b/sys/Makefile
@@ -1,11 +1,14 @@
 # $FreeBSD$
 
+.if !(make(cscope) || make(cscope-clean) || make(cscope-hook) || make(TAGS) || \
+    make(glimpse) || make(glimpse-clean))
 .include <src.opts.mk>
 
 # The boot loader
 .if ${MK_BOOT} != "no"
 SUBDIR=	boot
 .endif
+.endif
 
 # Directories to include in cscope name file and TAGS.
 CSCOPEDIRS=	boot bsm cam cddl compat conf contrib crypto ddb dev fs gdb \