diff --git a/src/Buffer.test.ts b/src/Buffer.test.ts
index db8a460d09..2561ce36df 100644
--- a/src/Buffer.test.ts
+++ b/src/Buffer.test.ts
@@ -7,7 +7,7 @@ import { assert, expect } from 'chai';
 import { ITerminal } from './Types';
 import { Buffer, DEFAULT_ATTR, CHAR_DATA_CHAR_INDEX } from './Buffer';
 import { CircularList } from './common/CircularList';
-import { MockTerminal, TestTerminal } from './utils/TestUtils.test';
+import { MockTerminal, TestTerminal } from './ui/TestUtils.test';
 import { BufferLine } from './BufferLine';
 
 const INIT_COLS = 80;
diff --git a/src/BufferSet.test.ts b/src/BufferSet.test.ts
index 38f2ddab93..26f9cd42f7 100644
--- a/src/BufferSet.test.ts
+++ b/src/BufferSet.test.ts
@@ -7,7 +7,7 @@ import { assert } from 'chai';
 import { ITerminal } from './Types';
 import { BufferSet } from './BufferSet';
 import { Buffer } from './Buffer';
-import { MockTerminal } from './utils/TestUtils.test';
+import { MockTerminal } from './ui/TestUtils.test';
 
 describe('BufferSet', () => {
   let terminal: ITerminal;
diff --git a/src/CharWidth.test.ts b/src/CharWidth.test.ts
index d4ddd24c5e..0747fdf12c 100644
--- a/src/CharWidth.test.ts
+++ b/src/CharWidth.test.ts
@@ -3,7 +3,7 @@
  * @license MIT
  */
 
-import { TestTerminal } from './utils/TestUtils.test';
+import { TestTerminal } from './ui/TestUtils.test';
 import { assert } from 'chai';
 import { getStringCellWidth, wcwidth } from './CharWidth';
 import { IBuffer } from './Types';
diff --git a/src/InputHandler.test.ts b/src/InputHandler.test.ts
index b2fea06a3c..acc18ea57a 100644
--- a/src/InputHandler.test.ts
+++ b/src/InputHandler.test.ts
@@ -5,7 +5,7 @@
 
 import { assert, expect } from 'chai';
 import { InputHandler } from './InputHandler';
-import { MockInputHandlingTerminal } from './utils/TestUtils.test';
+import { MockInputHandlingTerminal } from './ui/TestUtils.test';
 import { NULL_CELL_CHAR, NULL_CELL_CODE, NULL_CELL_WIDTH, CHAR_DATA_CHAR_INDEX, CHAR_DATA_ATTR_INDEX, DEFAULT_ATTR } from './Buffer';
 import { Terminal } from './Terminal';
 import { IBufferLine } from './Types';
diff --git a/src/Linkifier.test.ts b/src/Linkifier.test.ts
index 22e797aa7d..0ba1294a0e 100644
--- a/src/Linkifier.test.ts
+++ b/src/Linkifier.test.ts
@@ -7,7 +7,7 @@ import { assert } from 'chai';
 import { IMouseZoneManager, IMouseZone } from './ui/Types';
 import { ILinkMatcher, ITerminal, IBufferLine } from './Types';
 import { Linkifier } from './Linkifier';
-import { MockBuffer, MockTerminal, TestTerminal } from './utils/TestUtils.test';
+import { MockBuffer, MockTerminal, TestTerminal } from './ui/TestUtils.test';
 import { CircularList } from './common/CircularList';
 import { BufferLine } from './BufferLine';
 
diff --git a/src/SelectionManager.test.ts b/src/SelectionManager.test.ts
index 8735e8945d..2f74ccdab0 100644
--- a/src/SelectionManager.test.ts
+++ b/src/SelectionManager.test.ts
@@ -9,7 +9,7 @@ import { SelectionManager, SelectionMode } from './SelectionManager';
 import { SelectionModel } from './SelectionModel';
 import { BufferSet } from './BufferSet';
 import { ITerminal, IBuffer, IBufferLine } from './Types';
-import { MockTerminal } from './utils/TestUtils.test';
+import { MockTerminal } from './ui/TestUtils.test';
 import { BufferLine } from './BufferLine';
 
 class TestMockTerminal extends MockTerminal {
diff --git a/src/SelectionManager.ts b/src/SelectionManager.ts
index 3dc50271dc..4bac040055 100644
--- a/src/SelectionManager.ts
+++ b/src/SelectionManager.ts
@@ -5,7 +5,7 @@
 
 import { ITerminal, ISelectionManager, IBuffer, CharData, IBufferLine } from './Types';
 import { XtermListener } from './common/Types';
-import { MouseHelper } from './utils/MouseHelper';
+import { MouseHelper } from './ui/MouseHelper';
 import * as Browser from './core/Platform';
 import { CharMeasure } from './ui/CharMeasure';
 import { EventEmitter } from './common/EventEmitter';
diff --git a/src/SelectionModel.test.ts b/src/SelectionModel.test.ts
index 59b2ce75d0..8d4b30bb58 100644
--- a/src/SelectionModel.test.ts
+++ b/src/SelectionModel.test.ts
@@ -7,7 +7,7 @@ import { assert } from 'chai';
 import { ITerminal } from './Types';
 import { SelectionModel } from './SelectionModel';
 import { BufferSet } from './BufferSet';
-import { MockTerminal } from './utils/TestUtils.test';
+import { MockTerminal } from './ui/TestUtils.test';
 
 class TestSelectionModel extends SelectionModel {
   constructor(
diff --git a/src/Terminal.test.ts b/src/Terminal.test.ts
index fd59144c60..733d2b39bb 100644
--- a/src/Terminal.test.ts
+++ b/src/Terminal.test.ts
@@ -5,7 +5,7 @@
 
 import { assert, expect } from 'chai';
 import { Terminal } from './Terminal';
-import { MockViewport, MockCompositionHelper, MockRenderer } from './utils/TestUtils.test';
+import { MockViewport, MockCompositionHelper, MockRenderer } from './ui/TestUtils.test';
 import { CHAR_DATA_CHAR_INDEX, CHAR_DATA_WIDTH_INDEX, DEFAULT_ATTR } from './Buffer';
 
 const INIT_COLS = 80;
diff --git a/src/Terminal.ts b/src/Terminal.ts
index 779d9bf5e3..bc8fb103a2 100644
--- a/src/Terminal.ts
+++ b/src/Terminal.ts
@@ -39,8 +39,7 @@ import { CharMeasure } from './ui/CharMeasure';
 import * as Browser from './core/Platform';
 import { addDisposableDomListener } from './ui/Lifecycle';
 import * as Strings from './Strings';
-import { MouseHelper } from './utils/MouseHelper';
-import { clone } from './utils/Clone';
+import { MouseHelper } from './ui/MouseHelper';
 import { DEFAULT_BELL_SOUND, SoundManager } from './SoundManager';
 import { DEFAULT_ANSI_COLORS } from './renderer/ColorManager';
 import { MouseZoneManager } from './ui/MouseZoneManager';
@@ -52,6 +51,7 @@ import { DomRenderer } from './renderer/dom/DomRenderer';
 import { IKeyboardEvent } from './common/Types';
 import { evaluateKeyboardEvent } from './core/input/Keyboard';
 import { KeyboardResultType, ICharset } from './core/Types';
+import { clone } from './common/Clone';
 
 // Let it work inside Node.js for automated testing purposes.
 const document = (typeof window !== 'undefined') ? window.document : null;
diff --git a/src/utils/Clone.test.ts b/src/common/Clone.test.ts
similarity index 95%
rename from src/utils/Clone.test.ts
rename to src/common/Clone.test.ts
index b24452c89a..4b815ff36f 100644
--- a/src/utils/Clone.test.ts
+++ b/src/common/Clone.test.ts
@@ -101,7 +101,7 @@ describe('clone', () => {
     test.a.b.c.d.e.f = 'bar';
 
     // The values at a greater depth then 5 should not be cloned
-    assert.equal(cloned.a.b.c.d.e.f, 'bar');
+    assert.equal((cloned as any).a.b.c.d.e.f, 'bar');
   });
 
   it('should allow an optional maximum depth to be set', () => {
@@ -118,7 +118,7 @@ describe('clone', () => {
     test.a.b.c = 'bar';
 
     // The values at a greater depth then 2 should not be cloned
-    assert.equal(cloned.a.b.c, 'bar');
+    assert.equal((cloned as any).a.b.c, 'bar');
   });
 
   it('should not throw when cloning a recursive reference', () => {
diff --git a/src/utils/Clone.ts b/src/common/Clone.ts
similarity index 90%
rename from src/utils/Clone.ts
rename to src/common/Clone.ts
index b09c02584c..78bacbb521 100644
--- a/src/utils/Clone.ts
+++ b/src/common/Clone.ts
@@ -6,7 +6,7 @@
 /*
  * A simple utility for cloning values
  */
-export const clone = <T>(val: T, depth: number = 5): T => {
+export function clone<T>(val: T, depth: number = 5): T | null {
   if (typeof val !== 'object') {
     return val;
   }
@@ -25,4 +25,4 @@ export const clone = <T>(val: T, depth: number = 5): T => {
   }
 
   return clonedObject as T;
-};
+}
diff --git a/src/renderer/CharacterJoinerRegistry.test.ts b/src/renderer/CharacterJoinerRegistry.test.ts
index 383d2a7f8b..0c29566ac3 100644
--- a/src/renderer/CharacterJoinerRegistry.test.ts
+++ b/src/renderer/CharacterJoinerRegistry.test.ts
@@ -1,6 +1,6 @@
 import { assert } from 'chai';
 
-import { MockTerminal, MockBuffer } from '../utils/TestUtils.test';
+import { MockTerminal, MockBuffer } from '../ui/TestUtils.test';
 import { CircularList } from '../common/CircularList';
 
 import { ICharacterJoinerRegistry } from './Types';
diff --git a/src/utils/MouseHelper.test.ts b/src/ui/MouseHelper.test.ts
similarity index 100%
rename from src/utils/MouseHelper.test.ts
rename to src/ui/MouseHelper.test.ts
diff --git a/src/utils/MouseHelper.ts b/src/ui/MouseHelper.ts
similarity index 100%
rename from src/utils/MouseHelper.ts
rename to src/ui/MouseHelper.ts
diff --git a/src/utils/TestUtils.test.ts b/src/ui/TestUtils.test.ts
similarity index 100%
rename from src/utils/TestUtils.test.ts
rename to src/ui/TestUtils.test.ts