diff --git a/Makefile b/Makefile
index 7505a93..9461730 100755
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,10 @@ INPUTS = index.xml footer.xml
 SUBDIRS = about events docs office news users clubs media
 
 # the following two rules are there so cow gets built first.
-cow-first: events.ics recurse-cow books.xml members.xml menu.xml all
+cow-first: noroot events.ics recurse-cow books.xml members.xml menu.xml all
+
+noroot:
+	if test $$UID = 0; then echo "don't build as root!"; exit 1; fi
 
 recurse-cow:
 	cd cow && $(MAKE) && cd ..