diff --git a/src/cdk/observers/observe-content.ts b/src/cdk/observers/observe-content.ts
index f4775f04f33a..a13c57d5a7cc 100644
--- a/src/cdk/observers/observe-content.ts
+++ b/src/cdk/observers/observe-content.ts
@@ -76,9 +76,9 @@ export class ObserveContent implements AfterContentInit, OnDestroy {
 
     if (this._observer) {
       this._observer.observe(this._elementRef.nativeElement, {
-        characterData: true,
-        childList: true,
-        subtree: true
+        'characterData': true,
+        'childList': true,
+        'subtree': true
       });
     }
   }