diff --git a/client/config.sh b/client/config.sh
index 957b919e..74cd5a2e 100755
--- a/client/config.sh
+++ b/client/config.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-sed -i 's#https://api.zotero.org/#http://localhost:8080/#g' zotero-client/resource/config.js
-sed -i 's#wss://stream.zotero.org/#ws://localhost:8081/#g' zotero-client/resource/config.js
-sed -i 's#https://www.zotero.org/#http://localhost:8080/#g' zotero-client/resource/config.js
-sed -i 's#https://zoteroproxycheck.s3.amazonaws.com/test##g' zotero-client/resource/config.js
+sed -i'.bak' 's#https://api.zotero.org/#http://localhost:8080/#g' zotero-client/resource/config.js
+sed -i'.bak' 's#wss://stream.zotero.org/#ws://localhost:8081/#g' zotero-client/resource/config.js
+sed -i'.bak' 's#https://www.zotero.org/#http://localhost:8080/#g' zotero-client/resource/config.js
+sed -i'.bak' 's#https://zoteroproxycheck.s3.amazonaws.com/test##g' zotero-client/resource/config.js