diff --git a/ui/layouts/layout-base.d.ts b/ui/layouts/layout-base.d.ts
index 111147ab7..388bc5390 100644
--- a/ui/layouts/layout-base.d.ts
+++ b/ui/layouts/layout-base.d.ts
@@ -30,25 +30,25 @@
          * Adds the view to children array.
          * @param view The view to be added to the end of the children array.
          */
-        addChild(view: view.View);
+        addChild(view: view.View): void;
 
         /**
          * Inserts the view to children array at the specified index.
          * @param view The view to be added to the end of the children array.
          * @param atIndex The insertion index.
          */
-        insertChild(child: view.View, atIndex: number);
+        insertChild(child: view.View, atIndex: number): void;
 
         /**
          * Removes the specified view from the children array.
          * @param view The view to remove from the children array.
          */
-        removeChild(view: view.View);
+        removeChild(view: view.View): void;
 
         /**
          * Removes all views in this layout.
          */
-        removeChildren();
+        removeChildren(): void;
 
         /**
          * Gets or sets padding style property.
diff --git a/ui/layouts/layout-base.ts b/ui/layouts/layout-base.ts
index c7ba48a62..b5b6e77c1 100644
--- a/ui/layouts/layout-base.ts
+++ b/ui/layouts/layout-base.ts
@@ -37,18 +37,18 @@ export class LayoutBase extends view.CustomLayoutView implements definition.Layo
         return view.getViewById(this, id);
     }
 
-    public addChild(child: view.View) {
+    public addChild(child: view.View): void {
         // TODO: Do we need this method since we have the core logic in the View implementation?
         this._addView(child);
         this._subViews.push(child);
     }
 
-    public insertChild(child: view.View, atIndex: number) {
+    public insertChild(child: view.View, atIndex: number): void {
         this._addView(child, atIndex);
         this._subViews.splice(atIndex, 0, child);
     }
 
-    public removeChild(child: view.View) {
+    public removeChild(child: view.View): void {
         this._removeView(child);
 
         // TODO: consider caching the index on the child.
@@ -56,13 +56,13 @@ export class LayoutBase extends view.CustomLayoutView implements definition.Layo
         this._subViews.splice(index, 1);
     }
 
-    public removeChildren() {
+    public removeChildren(): void {
         while (this.getChildrenCount() != 0) {
             this.removeChild(this._subViews[this.getChildrenCount() - 1]);
         }
     }
 
-    public _eachChildView(callback: (child: view.View) => boolean) {
+    public _eachChildView(callback: (child: view.View) => boolean): void {
         var i;
         var length = this._subViews.length;
         var retVal: boolean;