diff --git a/lib/manager/components/transform/CustomCSVForm.js b/lib/manager/components/transform/CustomCSVForm.js
index b4f25aa40..dfd9aac11 100644
--- a/lib/manager/components/transform/CustomCSVForm.js
+++ b/lib/manager/components/transform/CustomCSVForm.js
@@ -17,6 +17,7 @@ type Props = {
   onChangeCsvData: ({target: {name?: string, value: string}}) => void,
   onSaveCsvData: () => void,
   placeholder?: string,
+  validateHeaders?: boolean
 }
 const CustomCSVForm = (props: Props) => {
   const [errorCount, setErrorCount] = useState(0)
@@ -34,9 +35,11 @@ const CustomCSVForm = (props: Props) => {
   } = props
 
   useEffect(() => {
+  // Default to true
+    const validateHeaders = props.validateHeaders !== undefined ? props.validateHeaders : true
     setErrorCount(0)
 
-    parseString(csvData, { headers: true })
+    parseString(csvData, { headers: validateHeaders })
       .on('error', _ => setErrorCount(errorCount + 1))
   }, [csvData])
 
diff --git a/lib/manager/components/transform/ReplaceFileFromString.js b/lib/manager/components/transform/ReplaceFileFromString.js
index 7dff5cc0a..ec963efd8 100644
--- a/lib/manager/components/transform/ReplaceFileFromString.js
+++ b/lib/manager/components/transform/ReplaceFileFromString.js
@@ -68,6 +68,7 @@ export default class ReplaceFileFromString extends Component<TransformProps<Repl
         inputIsSame={inputIsSame}
         onChangeCsvData={this._onChangeCsvData}
         onSaveCsvData={this._onSaveCsvData}
+        validateHeaders={transformation['@type'] !== 'AppendToFileTransformation'}
       />
     )
   }