diff --git a/src/cdk/observers/observe-content.ts b/src/cdk/observers/observe-content.ts
index 9d71aba87d1..3ba74c12269 100644
--- a/src/cdk/observers/observe-content.ts
+++ b/src/cdk/observers/observe-content.ts
@@ -75,9 +75,9 @@ export class CdkObserveContent implements AfterContentInit, OnDestroy {
 
     if (this._observer) {
       this._observer.observe(this._elementRef.nativeElement, {
-        characterData: true,
-        childList: true,
-        subtree: true
+        'characterData': true,
+        'childList': true,
+        'subtree': true
       });
     }
   }