diff --git a/demo/client.ts b/demo/client.ts
index fa98ee4ea1..7a60189848 100644
--- a/demo/client.ts
+++ b/demo/client.ts
@@ -172,7 +172,7 @@ function runFakeTerminal(): void {
       term.prompt();
     } else if (ev.keyCode === 8) {
      // Do not delete the prompt
-      if (term.x > 2) {
+      if (term._core.buffer.x > 2) {
         term.write('\b \b');
       }
     } else if (printable) {
diff --git a/src/AccessibilityManager.ts b/src/AccessibilityManager.ts
index fa0121ad0f..877676c97b 100644
--- a/src/AccessibilityManager.ts
+++ b/src/AccessibilityManager.ts
@@ -5,7 +5,7 @@
 
 import * as Strings from './Strings';
 import { ITerminal, IBuffer } from './Types';
-import { isMac } from './core/Platform';
+import { isMac } from './common/Platform';
 import { RenderDebouncer } from './ui/RenderDebouncer';
 import { addDisposableDomListener } from './ui/Lifecycle';
 import { Disposable } from './common/Lifecycle';
diff --git a/src/InputHandler.ts b/src/InputHandler.ts
index e43a614280..95eab4a330 100644
--- a/src/InputHandler.ts
+++ b/src/InputHandler.ts
@@ -896,7 +896,7 @@ export class InputHandler extends Disposable implements IInputHandler {
 
       while (param--) {
         buffer.lines.splice(buffer.ybase + buffer.scrollBottom, 1);
-        buffer.lines.splice(buffer.ybase + buffer.scrollBottom, 0, buffer.getBlankLine(DEFAULT_ATTR_DATA));
+        buffer.lines.splice(buffer.ybase + buffer.scrollTop, 0, buffer.getBlankLine(DEFAULT_ATTR_DATA));
       }
       // this.maxRange();
       this._terminal.updateRange(buffer.scrollTop);
diff --git a/src/SelectionManager.ts b/src/SelectionManager.ts
index 361b11235d..394808f616 100644
--- a/src/SelectionManager.ts
+++ b/src/SelectionManager.ts
@@ -6,7 +6,7 @@
 import { ITerminal, ISelectionManager, IBuffer, IBufferLine } from './Types';
 import { XtermListener } from './common/Types';
 import { MouseHelper } from './ui/MouseHelper';
-import * as Browser from './core/Platform';
+import * as Browser from './common/Platform';
 import { CharMeasure } from './ui/CharMeasure';
 import { EventEmitter } from './common/EventEmitter';
 import { SelectionModel } from './SelectionModel';
diff --git a/src/Terminal.ts b/src/Terminal.ts
index 50ff26d52d..7eab1c88bd 100644
--- a/src/Terminal.ts
+++ b/src/Terminal.ts
@@ -36,7 +36,7 @@ import { Renderer } from './renderer/Renderer';
 import { Linkifier } from './Linkifier';
 import { SelectionManager } from './SelectionManager';
 import { CharMeasure } from './ui/CharMeasure';
-import * as Browser from './core/Platform';
+import * as Browser from './common/Platform';
 import { addDisposableDomListener } from './ui/Lifecycle';
 import * as Strings from './Strings';
 import { MouseHelper } from './ui/MouseHelper';
diff --git a/src/common/EventEmitter.ts b/src/common/EventEmitter.ts
index 68eb60f7a5..74a794cd0e 100644
--- a/src/common/EventEmitter.ts
+++ b/src/common/EventEmitter.ts
@@ -3,8 +3,7 @@
  * @license MIT
  */
 
-import { XtermListener } from './Types';
-import { IEventEmitter, IDisposable } from 'xterm';
+import { IDisposable, IEventEmitter, XtermListener } from './Types';
 import { Disposable } from './Lifecycle';
 
 export class EventEmitter extends Disposable implements IEventEmitter, IDisposable {
diff --git a/src/common/Lifecycle.ts b/src/common/Lifecycle.ts
index 209a3e2ac5..5fac6e8251 100644
--- a/src/common/Lifecycle.ts
+++ b/src/common/Lifecycle.ts
@@ -3,7 +3,7 @@
  * @license MIT
  */
 
-import { IDisposable } from 'xterm';
+import { IDisposable } from './Types';
 
 /**
  * A base class that can be extended to provide convenience methods for managing the lifecycle of an
diff --git a/src/core/Platform.ts b/src/common/Platform.ts
similarity index 82%
rename from src/core/Platform.ts
rename to src/common/Platform.ts
index 42c20d9d24..ee82cff4fb 100644
--- a/src/core/Platform.ts
+++ b/src/common/Platform.ts
@@ -3,6 +3,16 @@
  * @license MIT
  */
 
+interface INavigator {
+  userAgent: string;
+  language: string;
+  platform: string;
+}
+
+// We're declaring a navigator global here as we expect it in all runtimes (node and browser), but
+// we want this module to live in common.
+declare const navigator: INavigator;
+
 const isNode = (typeof navigator === 'undefined') ? true : false;
 const userAgent = (isNode) ? 'node' : navigator.userAgent;
 const platform = (isNode) ? 'node' : navigator.platform;
diff --git a/src/common/Types.ts b/src/common/Types.ts
index 8a416bf1ab..8ad98d99cc 100644
--- a/src/common/Types.ts
+++ b/src/common/Types.ts
@@ -3,7 +3,16 @@
  * @license MIT
  */
 
-import { IEventEmitter } from 'xterm';
+export interface IDisposable {
+  dispose(): void;
+}
+
+export interface IEventEmitter {
+  on(type: string, listener: (...args: any[]) => void): void;
+  off(type: string, listener: (...args: any[]) => void): void;
+  emit(type: string, data?: any): void;
+  addDisposableListener(type: string, handler: (...args: any[]) => void): IDisposable;
+}
 
 export type XtermListener = (...args: any[]) => void;
 
diff --git a/src/common/tsconfig.json b/src/common/tsconfig.json
index b40bb2f500..ccf742e5f7 100644
--- a/src/common/tsconfig.json
+++ b/src/common/tsconfig.json
@@ -1,9 +1,10 @@
 {
   "extends": "../tsconfig-library-base",
   "compilerOptions": {
-    "outDir": "../../lib"
+    "outDir": "../../lib",
+    "types": [
+      "../../node_modules/@types/mocha"
+    ]
   },
-  "include": [
-    "./**/*"
-  ]
+  "include": [ "./**/*" ]
 }
diff --git a/src/core/tsconfig.json b/src/core/tsconfig.json
index 41e41f0c12..99bf48ca7c 100644
--- a/src/core/tsconfig.json
+++ b/src/core/tsconfig.json
@@ -1,11 +1,12 @@
 {
   "extends": "../tsconfig-library-base",
   "compilerOptions": {
-    "outDir": "../../lib"
+    "outDir": "../../lib",
+    "types": [
+      "../../node_modules/@types/mocha"
+    ]
   },
-  "include": [
-    "./**/*"
-  ],
+  "include": [ "./**/*" ],
   "references": [
     { "path": "../common" }
   ]
diff --git a/src/renderer/atlas/CharAtlasGenerator.ts b/src/renderer/atlas/CharAtlasGenerator.ts
index cadcce2ec1..389507661e 100644
--- a/src/renderer/atlas/CharAtlasGenerator.ts
+++ b/src/renderer/atlas/CharAtlasGenerator.ts
@@ -4,7 +4,7 @@
  */
 
 import { FontWeight } from 'xterm';
-import { isFirefox, isSafari } from '../../core/Platform';
+import { isFirefox, isSafari } from '../../common/Platform';
 import { IColor } from '../Types';
 import { ICharAtlasConfig, CHAR_ATLAS_CELL_SPACING } from './Types';
 
diff --git a/src/renderer/atlas/DynamicCharAtlas.ts b/src/renderer/atlas/DynamicCharAtlas.ts
index e311c369a3..cb03a48f94 100644
--- a/src/renderer/atlas/DynamicCharAtlas.ts
+++ b/src/renderer/atlas/DynamicCharAtlas.ts
@@ -8,7 +8,7 @@ import BaseCharAtlas from './BaseCharAtlas';
 import { DEFAULT_ANSI_COLORS } from '../ColorManager';
 import { clearColor } from './CharAtlasGenerator';
 import LRUMap from './LRUMap';
-import { isFirefox, isSafari } from '../../core/Platform';
+import { isFirefox, isSafari } from '../../common/Platform';
 import { IColor } from '../Types';
 
 // In practice we're probably never going to exhaust a texture this large. For debugging purposes,
diff --git a/src/tsconfig-base.json b/src/tsconfig-base.json
index 5c6afcc5b0..84d0c924de 100644
--- a/src/tsconfig-base.json
+++ b/src/tsconfig-base.json
@@ -8,8 +8,6 @@
     "removeComments": true,
     "pretty": true,
 
-    "incremental": true,
-
-    "skipLibCheck": true
+    "incremental": true
   }
 }
diff --git a/src/tsconfig-library-base.json b/src/tsconfig-library-base.json
index c82e087351..66b61f09e1 100644
--- a/src/tsconfig-library-base.json
+++ b/src/tsconfig-library-base.json
@@ -1,10 +1,6 @@
 {
   "extends": "./tsconfig-base.json",
   "compilerOptions": {
-    "types": [
-      "../../node_modules/@types/mocha",
-      "../../"
-    ],
     "composite": true,
     "strict": true
   }
diff --git a/src/tsconfig.json b/src/tsconfig.json
index 0aa3abb884..f0b1c7490d 100644
--- a/src/tsconfig.json
+++ b/src/tsconfig.json
@@ -11,7 +11,7 @@
     ],
     "rootDir": ".",
     "outDir": "../lib",
-    
+
     "noUnusedLocals": true,
     "noImplicitAny": true
   },
@@ -27,4 +27,3 @@
     { "path": "./core" }
   ]
 }
-  
\ No newline at end of file
diff --git a/src/ui/TestUtils.test.ts b/src/ui/TestUtils.test.ts
index 4772a9d8c2..d6b2d559cf 100644
--- a/src/ui/TestUtils.test.ts
+++ b/src/ui/TestUtils.test.ts
@@ -7,7 +7,7 @@ import { IColorSet, IRenderer, IRenderDimensions, IColorManager } from '../rende
 import { IInputHandlingTerminal, IViewport, ICompositionHelper, ITerminal, IBuffer, IBufferSet, IBrowser, ICharMeasure, ISelectionManager, ITerminalOptions, ILinkifier, IMouseHelper, ILinkMatcherOptions, CharacterJoinerHandler, IBufferLine, IBufferStringIterator, ICellData, IAttributeData } from '../Types';
 import { ICircularList, XtermListener } from '../common/Types';
 import { Buffer } from '../Buffer';
-import * as Browser from '../core/Platform';
+import * as Browser from '../common/Platform';
 import { ITheme, IDisposable, IMarker } from 'xterm';
 import { Terminal } from '../Terminal';
 import { AttributeData } from '../BufferLine';