diff --git a/runtime/doc/Makefile b/runtime/doc/Makefile
index d60501e..e4b2b5b 100644
--- a/runtime/doc/Makefile
+++ b/runtime/doc/Makefile
@@ -375,6 +375,10 @@
 perlhtml: tags $(DOCS)
 	./vim2html.pl tags $(DOCS)
 
+# Check URLs in the help with "curl".
+test_urls:
+	vim -S test_urls.vim
+
 clean:
 	-rm doctags *.html tags.ref