diff --git a/src/browser/Terminal.ts b/src/browser/Terminal.ts
index 98ed8b9a..31ef1287 100644
--- a/src/browser/Terminal.ts
+++ b/src/browser/Terminal.ts
@@ -583,7 +583,7 @@ export class Terminal extends CoreTerminal implements ITerminal {
     this.register(this.onScroll(() => this._mouseZoneManager!.clearAll()));
     this.linkifier.attachToDom(this.element, this._mouseZoneManager);
     this.linkifier2.attachToDom(this.screenElement, this._mouseService, this._renderService);
-    this._instantiationService.createInstance(BufferDecorationRenderer, this.screenElement);
+    this.register(this._instantiationService.createInstance(BufferDecorationRenderer, this.screenElement));
     // This event listener must be registered aftre MouseZoneManager is created
     this.register(addDisposableDomListener(this.element, 'mousedown', (e: MouseEvent) => this._selectionService!.onMouseDown(e)));
 
@@ -1016,7 +1016,7 @@ export class Terminal extends CoreTerminal implements ITerminal {
   }
 
   public registerDecoration(decorationOptions: IDecorationOptions): IDecoration | undefined {
-    return this._decorationService!.registerDecoration(decorationOptions);
+    return this._decorationService.registerDecoration(decorationOptions);
   }
 
   /**
diff --git a/src/browser/tsconfig.json b/src/browser/tsconfig.json
index fc997477..212aeab8 100644
--- a/src/browser/tsconfig.json
+++ b/src/browser/tsconfig.json
@@ -18,7 +18,7 @@
   "include": [
     "./**/*",
     "../../typings/xterm.d.ts"
-],
+  ],
   "references": [
     { "path": "../common" }
   ]
diff --git a/typings/xterm.d.ts b/typings/xterm.d.ts
index 940e3a48..24ba940e 100644
--- a/typings/xterm.d.ts
+++ b/typings/xterm.d.ts
@@ -268,7 +268,8 @@ declare module 'xterm' {
     windowOptions?: IWindowOptions;
 
     /**
-     * The width, in pixels, of the canvas for the overview ruler.
+     * The width, in pixels, of the canvas for the overview ruler. The overview
+     * ruler will be hidden when not set.
      */
     overviewRulerWidth?: number;
   }
@@ -399,7 +400,7 @@ declare module 'xterm' {
   }
 
   /**
-   * Represents a disposable with an
+   * Represents a disposable that tracks is disposed state.
    * @param onDispose event listener and
    * @param isDisposed property.
    */