diff --git a/Makefile b/Makefile
index 1be4f1e7ef..0c6951c9bf 100644
--- a/Makefile
+++ b/Makefile
@@ -194,9 +194,7 @@ godocs:
 # the `versions` file will be the default root index.html.
 build-docs:
 	@cd docs && \
-	while read -a p; do \
-		branch=$${p[0]} ; \
-		path_prefix=$${p[1]} ; \
+	while read -r branch path_prefix; do \
 		(git checkout $${branch} && npm install && VUEPRESS_BASE="/$${path_prefix}/" npm run build) ; \
 		mkdir -p ~/output/$${path_prefix} ; \
 		cp -r .vuepress/dist/* ~/output/$${path_prefix}/ ; \