diff --git a/src/vs/editor/common/model.ts b/src/vs/editor/common/model.ts
index 3ce343c74113c31e0ed61817d6ce5357f3657fc6..6c208408ba30e16679b904eab3633fe464c3225f 100644
--- a/src/vs/editor/common/model.ts
+++ b/src/vs/editor/common/model.ts
@@ -1088,7 +1088,7 @@ export interface ITextBuffer {
 	getLineFirstNonWhitespaceColumn(lineNumber: number): number;
 	getLineLastNonWhitespaceColumn(lineNumber: number): number;
 
-	setEOL(newEOL: string): void;
+	setEOL(newEOL: '\r\n' | '\n'): void;
 	applyEdits(rawOperations: IIdentifiedSingleEditOperation[], recordTrimAutoWhitespace: boolean): ApplyEditsResult;
 }
 
diff --git a/src/vs/editor/common/model/linesTextBuffer/linesTextBuffer.ts b/src/vs/editor/common/model/linesTextBuffer/linesTextBuffer.ts
index 6b451df0c51a48c4fda6cb2a496c1198bb7ef8c3..af20bfb5ade6532b03c7cb85a33b8e50a987fa15 100644
--- a/src/vs/editor/common/model/linesTextBuffer/linesTextBuffer.ts
+++ b/src/vs/editor/common/model/linesTextBuffer/linesTextBuffer.ts
@@ -232,7 +232,7 @@ export class LinesTextBuffer implements ITextBuffer {
 
 	//#region Editing
 
-	public setEOL(newEOL: string): void {
+	public setEOL(newEOL: '\r\n' | '\n'): void {
 		this._EOL = newEOL;
 		this._constructLineStarts();
 	}