diff --git a/src/vs/workbench/api/node/extHost.api.impl.ts b/src/vs/workbench/api/node/extHost.api.impl.ts
index ec999b36e46..a6ba7257639 100644
--- a/src/vs/workbench/api/node/extHost.api.impl.ts
+++ b/src/vs/workbench/api/node/extHost.api.impl.ts
@@ -246,11 +246,11 @@ export function createApiFactory(
 			get appRoot() { return initData.environment.appRoot.fsPath; },
 			get logLevel() {
 				checkProposedApiEnabled(extension);
-				return typeConverters.LogLevel.fromMainLogLevel(extHostLogService.getLevel());
+				return typeConverters.LogLevel.to(extHostLogService.getLevel());
 			},
 			get onDidChangeLogLevel() {
 				checkProposedApiEnabled(extension);
-				return mapEvent(extHostLogService.onDidChangeLogLevel, l => typeConverters.LogLevel.fromMainLogLevel(l));
+				return mapEvent(extHostLogService.onDidChangeLogLevel, l => typeConverters.LogLevel.to(l));
 			},
 			get clipboard(): vscode.Clipboard {
 				return extHostClipboard;
diff --git a/src/vs/workbench/api/node/extHostTypeConverters.ts b/src/vs/workbench/api/node/extHostTypeConverters.ts
index 8cf7f76930d..7cc4c9f0761 100644
--- a/src/vs/workbench/api/node/extHostTypeConverters.ts
+++ b/src/vs/workbench/api/node/extHostTypeConverters.ts
@@ -970,11 +970,49 @@ export namespace LanguageSelector {
 }
 
 export namespace LogLevel {
-	export function fromMainLogLevel(mainLevel: _MainLogLevel): types.LogLevel {
-		return mainLevel + 1;
+	export function from(extLevel: types.LogLevel): _MainLogLevel {
+		switch (extLevel) {
+			case types.LogLevel.Trace:
+				return _MainLogLevel.Trace;
+			case types.LogLevel.Debug:
+				return _MainLogLevel.Debug;
+			case types.LogLevel.Info:
+				return _MainLogLevel.Info;
+			case types.LogLevel.Warning:
+				return _MainLogLevel.Warning;
+			case types.LogLevel.Error:
+				return _MainLogLevel.Error;
+			case types.LogLevel.Critical:
+				return _MainLogLevel.Critical;
+			case types.LogLevel.Critical:
+				return _MainLogLevel.Critical;
+			case types.LogLevel.Off:
+				return _MainLogLevel.Off;
+		}
+
+		return _MainLogLevel.Info;
 	}
 
-	export function toMainLogLevel(extLevel: types.LogLevel): _MainLogLevel {
-		return extLevel - 1;
+	export function to(mainLevel: _MainLogLevel): types.LogLevel {
+		switch (mainLevel) {
+			case _MainLogLevel.Trace:
+				return types.LogLevel.Trace;
+			case _MainLogLevel.Debug:
+				return types.LogLevel.Debug;
+			case _MainLogLevel.Info:
+				return types.LogLevel.Info;
+			case _MainLogLevel.Warning:
+				return types.LogLevel.Warning;
+			case _MainLogLevel.Error:
+				return types.LogLevel.Error;
+			case _MainLogLevel.Critical:
+				return types.LogLevel.Critical;
+			case _MainLogLevel.Critical:
+				return types.LogLevel.Critical;
+			case _MainLogLevel.Off:
+				return types.LogLevel.Off;
+		}
+
+		return types.LogLevel.Info;
 	}
 }
diff --git a/src/vs/workbench/test/electron-browser/api/extHostTypeConverter.test.ts b/src/vs/workbench/test/electron-browser/api/extHostTypeConverter.test.ts
index 3b217231a5f..7f67a1cea9d 100644
--- a/src/vs/workbench/test/electron-browser/api/extHostTypeConverter.test.ts
+++ b/src/vs/workbench/test/electron-browser/api/extHostTypeConverter.test.ts
@@ -5,9 +5,11 @@
 
 
 import * as assert from 'assert';
-import { MarkdownString } from 'vs/workbench/api/node/extHostTypeConverters';
+import { MarkdownString, LogLevel } from 'vs/workbench/api/node/extHostTypeConverters';
 import { isEmptyObject } from 'vs/base/common/types';
 import { size } from 'vs/base/common/collections';
+import * as types from 'vs/workbench/api/node/extHostTypes';
+import { LogLevel as _MainLogLevel } from 'vs/platform/log/common/log';
 
 suite('ExtHostTypeConverter', function () {
 
@@ -56,4 +58,14 @@ suite('ExtHostTypeConverter', function () {
 		assert.ok(!!data.uris['file:///somepath/here']);
 		assert.ok(!!data.uris['file:///somepath/here2']);
 	});
+
+	test('LogLevel', () => {
+		assert.equal(LogLevel.from(types.LogLevel.Error), _MainLogLevel.Error);
+		assert.equal(LogLevel.from(types.LogLevel.Info), _MainLogLevel.Info);
+		assert.equal(LogLevel.from(types.LogLevel.Off), _MainLogLevel.Off);
+
+		assert.equal(LogLevel.to(_MainLogLevel.Error), types.LogLevel.Error);
+		assert.equal(LogLevel.to(_MainLogLevel.Info), types.LogLevel.Info);
+		assert.equal(LogLevel.to(_MainLogLevel.Off), types.LogLevel.Off);
+	});
 });