diff --git a/src/vs/editor/common/editorCommon.ts b/src/vs/editor/common/editorCommon.ts
index 01adf812f76991862a3cd4cad6d9a115c70f041f..b1973d71978bff4dd14a56bd592fa4c18f5d2430 100644
--- a/src/vs/editor/common/editorCommon.ts
+++ b/src/vs/editor/common/editorCommon.ts
@@ -1859,6 +1859,10 @@ export interface IModelContentChangedEvent2 {
 	 * The new text for the range.
 	 */
 	text: string;
+	/**
+	 * The end-of-line character.
+	 */
+	eol: string;
 	/**
 	 * The new version id the model has transitioned to.
 	 */
diff --git a/src/vs/editor/common/model/mirrorModel2.ts b/src/vs/editor/common/model/mirrorModel2.ts
index ae70ac947abdf3cf84e51d60d54e468ac79ed43e..d9ffd7f121c9454ecc0b7d7d797dc29989a965d8 100644
--- a/src/vs/editor/common/model/mirrorModel2.ts
+++ b/src/vs/editor/common/model/mirrorModel2.ts
@@ -36,6 +36,18 @@ export class MirrorModel2 {
 	}
 
 	onEvents(events: IModelContentChangedEvent2[]): void {
+		let newEOL: string = null;
+		for (let i = 0, len = events.length; i < len; i++) {
+			let e = events[i];
+			if (e.eol) {
+				newEOL = e.eol;
+			}
+		}
+		if (newEOL && newEOL !== this._eol) {
+			this._eol = newEOL;
+			this._lineStarts = null;
+		}
+
 		// Update my lines
 		let lastVersionId = -1;
 		for (let i = 0, len = events.length; i < len; i++) {
diff --git a/src/vs/editor/common/model/textModel.ts b/src/vs/editor/common/model/textModel.ts
index f74be8b2830dac4166e5a8a75b1f32384a38ffbc..8f627eaeb11a0818b8b0b03c03b78972e7a4c91b 100644
--- a/src/vs/editor/common/model/textModel.ts
+++ b/src/vs/editor/common/model/textModel.ts
@@ -124,6 +124,7 @@ export class TextModel extends OrderGuaranteeEventEmitter implements EditorCommo
 			range: new Range(startLineNumber, startColumn, endLineNumber, endColumn),
 			rangeLength: rangeLength,
 			text: text,
+			eol: this._EOL,
 			versionId: this.getVersionId(),
 			isUndoing: isUndoing,
 			isRedoing: isRedoing
diff --git a/src/vs/editor/test/common/model/editableTextModel.test.ts b/src/vs/editor/test/common/model/editableTextModel.test.ts
index ad3c7bd69d1ba28bbc13d471af4cea8ea460d504..af35fdc1632aa216c0c612763ca4bf7e44cde5d4 100644
--- a/src/vs/editor/test/common/model/editableTextModel.test.ts
+++ b/src/vs/editor/test/common/model/editableTextModel.test.ts
@@ -1284,6 +1284,35 @@ suite('EditorModel - EditableTextModel.applyEdits', () => {
 			});
 		});
 	});
+
+	test('issue #1580: Changes in line endings are not correctly reflected in the extension host, leading to invalid offsets sent to external refactoring tools', () => {
+		let model = new EditableTextModel([], TextModel.toRawText('Hello\nWorld!'), null);
+		assert.equal(model.getEOL(), '\n');
+
+		let mirrorModel2 = new MirrorModel2(null, model.toRawText().lines, model.toRawText().EOL, model.getVersionId());
+		let mirrorModel2PrevVersionId = model.getVersionId();
+
+		model.addListener(EditorCommon.EventType.ModelContentChanged2, (e:EditorCommon.IModelContentChangedEvent2) => {
+			let versionId = e.versionId;
+			if (versionId < mirrorModel2PrevVersionId) {
+				console.warn('Model version id did not advance between edits (2)');
+			}
+			mirrorModel2PrevVersionId = versionId;
+			mirrorModel2.onEvents([e]);
+		});
+
+		let assertMirrorModels = () => {
+			model._assertLineNumbersOK();
+			assert.equal(mirrorModel2.getText(), model.getValue(), 'mirror model 2 text OK');
+			assert.equal(mirrorModel2.version, model.getVersionId(), 'mirror model 2 version OK');
+		};
+
+		model.setEOL(EditorCommon.EndOfLineSequence.CRLF);
+		assertMirrorModels();
+
+		model.dispose();
+		mirrorModel2.dispose();
+	});
 });
 
 interface ILightWeightMarker {
diff --git a/src/vs/workbench/test/common/api/extHostDocuments.test.ts b/src/vs/workbench/test/common/api/extHostDocuments.test.ts
index 88ebddaab7b446b2414b40b33b6f93f808b39b79..12f54da0720aef1a073241fcaf1742fb1a222e0c 100644
--- a/src/vs/workbench/test/common/api/extHostDocuments.test.ts
+++ b/src/vs/workbench/test/common/api/extHostDocuments.test.ts
@@ -69,6 +69,7 @@ suite("PluginHostDocument", () => {
 		data.onEvents([{
 			range: { startLineNumber: 1, startColumn: 1, endLineNumber: 1, endColumn: 1 },
 			text: '\t ',
+			eol: undefined,
 			isRedoing: undefined,
 			isUndoing: undefined,
 			versionId: undefined,
@@ -105,6 +106,7 @@ suite("PluginHostDocument", () => {
 		data.onEvents([{
 			range: { startLineNumber: 1, startColumn: 3, endLineNumber: 1, endColumn: 6 },
 			text: '',
+			eol: undefined,
 			isRedoing: undefined,
 			isUndoing: undefined,
 			versionId: undefined,
@@ -121,6 +123,7 @@ suite("PluginHostDocument", () => {
 		data.onEvents([{
 			range: { startLineNumber: 1, startColumn: 3, endLineNumber: 1, endColumn: 6 },
 			text: 'is could be',
+			eol: undefined,
 			isRedoing: undefined,
 			isUndoing: undefined,
 			versionId: undefined,
@@ -137,6 +140,7 @@ suite("PluginHostDocument", () => {
 		data.onEvents([{
 			range: { startLineNumber: 1, startColumn: 3, endLineNumber: 1, endColumn: 6 },
 			text: 'is could be\na line with number',
+			eol: undefined,
 			isRedoing: undefined,
 			isUndoing: undefined,
 			versionId: undefined,
@@ -156,6 +160,7 @@ suite("PluginHostDocument", () => {
 		data.onEvents([{
 			range: { startLineNumber: 1, startColumn: 3, endLineNumber: 2, endColumn: 6 },
 			text: '',
+			eol: undefined,
 			isRedoing: undefined,
 			isUndoing: undefined,
 			versionId: undefined,
@@ -222,10 +227,11 @@ suite("PluginHostDocument updates line mapping", () => {
 		}
 	}
 
-	function createChangeEvent(range:CodeEditorRange, text:string): EditorCommon.IModelContentChangedEvent2 {
+	function createChangeEvent(range:CodeEditorRange, text:string, eol?:string): EditorCommon.IModelContentChangedEvent2 {
 		return {
 			range: range,
 			text: text,
+			eol: eol,
 			isRedoing: undefined,
 			isUndoing: undefined,
 			versionId: undefined,
@@ -329,4 +335,22 @@ suite("PluginHostDocument updates line mapping", () => {
 			'and finished with the fourth.',
 		], [createChangeEvent(new CodeEditorRange(1, 3, 4, 30), 'some new text\nthat\nspans multiple lines')]);
 	});
+
+	test('after changing EOL to CRLF', () => {
+		testLineMappingAfterEvents([
+			'This is line one',
+			'and this is line number two',
+			'it is followed by #3',
+			'and finished with the fourth.',
+		], [createChangeEvent(new CodeEditorRange(1, 1, 1, 1), '', '\r\n')]);
+	});
+
+	test('after changing EOL to LF', () => {
+		testLineMappingAfterEvents([
+			'This is line one',
+			'and this is line number two',
+			'it is followed by #3',
+			'and finished with the fourth.',
+		], [createChangeEvent(new CodeEditorRange(1, 1, 1, 1), '', '\n')]);
+	});
 });
\ No newline at end of file