diff --git a/lib/manager/components/deployment/CustomConfig.js b/lib/manager/components/deployment/CustomConfig.js
index bb5f610d4..a7c9903c0 100644
--- a/lib/manager/components/deployment/CustomConfig.js
+++ b/lib/manager/components/deployment/CustomConfig.js
@@ -44,7 +44,7 @@ export default class CustomConfig extends Component<{
 }, {[string]: any}> {
   state = {}
 
-  getName = (option: string) => {
+  getName = (option?: string) => {
     let {name} = this.props
     if (option === CONFIG_OPTIONS.url) {
       name += 'Url'
@@ -80,7 +80,7 @@ export default class CustomConfig extends Component<{
     this.setState({[name]: evt.target.value})
   }
 
-  _onSaveConfig = (option) => {
+  _onSaveConfig = (option?: string) => {
     const {deployment, updateDeployment} = this.props
     const name = this.getName(option)