diff --git a/Makefile.in b/Makefile.in
index 5ff3efe0..644ed713 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -204,8 +204,8 @@ install: all copy-files
 	chmod 755 ejabberd.init
 	#
 	# Service script
-	$(SED) -e "s*@ctlscriptpath@*$(SBINDIR)*g" ejabberd.service.template \
-		> ejabberd.service
+	[ -f ejabberd.service ] || $(SED) -e "s*@ctlscriptpath@*$(SBINDIR)*g" \
+		ejabberd.service.template > ejabberd.service
 	chmod 644 ejabberd.service
 	#
 	# Spool directory