diff --git a/packages/common/src/directives/ng_for_of.ts b/packages/common/src/directives/ng_for_of.ts
index ed3beeca5c..08feff2183 100644
--- a/packages/common/src/directives/ng_for_of.ts
+++ b/packages/common/src/directives/ng_for_of.ts
@@ -190,6 +190,9 @@ export class NgForOf<T> implements DoCheck {
     }
   }
 
+  /**
+   * Applies the changes when needed.
+   */
   ngDoCheck(): void {
     if (this._ngForOfDirty) {
       this._ngForOfDirty = false;