diff --git a/Makefile.org b/Makefile.org
index 19d02066b..8f92dd1a1 100644
--- a/Makefile.org
+++ b/Makefile.org
@@ -468,7 +468,7 @@ tags:
 errors:
 	$(PERL) util/mkerr.pl -recurse -write
 	(cd engines; $(MAKE) PERL=$(PERL) errors)
-	$(PERL) util/ck_errf.pl */*.c */*/*.c
+	$(PERL) util/ck_errf.pl -strict */*.c */*/*.c
 
 stacks:
 	$(PERL) util/mkstack.pl -write