diff --git a/Makefile b/Makefile
index 0d2151dae10e..7dafc36ebcbf 100644
--- a/Makefile
+++ b/Makefile
@@ -240,17 +240,15 @@ ${TGTS}:
 
 # The historic default "all" target creates files which may cause stale
 # or (in the cross build case) unlinkable results. Fail with an error
-# when no target is given. The users can set ALLOW_IMPLICIT_TARGET or
-# explicitly specify "all" if they want the historic behavior.
-.ifdef ALLOW_IMPLICIT_TARGET
-.MAIN:	all
-.else
+# when no target is given. The users can explicitly specify "all"
+# if they want the historic behavior.
 .MAIN:	_guard
 
 _guard:
-	@echo "Use an explicit target or set ALLOW_IMPLICIT_TARGET"
+	@echo
+	@echo "Explicit target required (use \"all\" for historic behavior)"
+	@echo
 	@false
-.endif
 
 STARTTIME!= LC_ALL=C date
 CHECK_TIME!= find ${.CURDIR}/sys/sys/param.h -mtime -0s ; echo