diff --git a/lib/Makefile.am b/lib/Makefile.am
index 15dbcd290e9873cda51d1aa676f7ff578d665450..0e80f5e1858f1ec8c39cb1e925a4f04b8594f613 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -188,6 +188,6 @@ $(VCPROJ): vc8proj.head vc8proj.foot Makefile.am
 if CURLDEBUG
 # for debug builds, we scan the sources on all regular make invokes
 all-local:
-	@for i in $(CSOURCES) $(HHEADERS); do @PERL@ $(top_srcdir)/lib/checksrc.pl $(top_srcdir)/lib/$$i; if test $$? != "0"; then exit 1; fi; done
+	@@PERL@ $(top_srcdir)/lib/checksrc.pl -D$(top_srcdir)/lib $(CSOURCES) $(HHEADERS)
 endif