diff --git a/src/vs/workbench/api/common/extHost.protocol.ts b/src/vs/workbench/api/common/extHost.protocol.ts
index 8e66c4caac7..058d27c3c4e 100644
--- a/src/vs/workbench/api/common/extHost.protocol.ts
+++ b/src/vs/workbench/api/common/extHost.protocol.ts
@@ -216,7 +216,7 @@ export interface IUndoStopOptions {
 }
 
 export interface IApplyEditsOptions extends IUndoStopOptions {
-	setEndOfLine: EndOfLineSequence;
+	setEndOfLine?: EndOfLineSequence;
 }
 
 export interface ITextDocumentShowOptions {
diff --git a/src/vs/workbench/api/electron-browser/mainThreadEditor.ts b/src/vs/workbench/api/electron-browser/mainThreadEditor.ts
index ffded166349..b0cb211ea1d 100644
--- a/src/vs/workbench/api/electron-browser/mainThreadEditor.ts
+++ b/src/vs/workbench/api/electron-browser/mainThreadEditor.ts
@@ -447,7 +447,9 @@ export class MainThreadTextEditor {
 			return false;
 		}
 
-		this._model.pushEOL(opts.setEndOfLine);
+		if (typeof opts.setEndOfLine !== 'undefined') {
+			this._model.pushEOL(opts.setEndOfLine);
+		}
 
 		const transformedEdits = edits.map((edit): IIdentifiedSingleEditOperation => {
 			return {
diff --git a/src/vs/workbench/api/node/extHostTextEditor.ts b/src/vs/workbench/api/node/extHostTextEditor.ts
index c795cc98d8c..2cabc90f797 100644
--- a/src/vs/workbench/api/node/extHostTextEditor.ts
+++ b/src/vs/workbench/api/node/extHostTextEditor.ts
@@ -607,7 +607,7 @@ export class ExtHostTextEditor implements vscode.TextEditor {
 		});
 
 		return this._proxy.$tryApplyEdits(this._id, editData.documentVersionId, edits, {
-			setEndOfLine: TypeConverters.EndOfLine.from(editData.setEndOfLine),
+			setEndOfLine: editData.setEndOfLine && TypeConverters.EndOfLine.from(editData.setEndOfLine),
 			undoStopBefore: editData.undoStopBefore,
 			undoStopAfter: editData.undoStopAfter
 		});