diff --git a/test/unit/property-effects.html b/test/unit/property-effects.html
index 0481f2411b..c9c3c1355a 100644
--- a/test/unit/property-effects.html
+++ b/test/unit/property-effects.html
@@ -1508,16 +1508,20 @@
 
 suite('a la carte usage of API', function() {
 
-  class BaseClass extends Polymer.PropertyEffects(HTMLElement) {
-    connectedCallback() {
-      this.pcSpy = sinon.spy();
-      this._flushProperties();
-    }
-    _propertiesChanged(props, changedProps, oldProps) {
-      this.pcSpy(props, changedProps, oldProps);
-      super._propertiesChanged(props, changedProps, oldProps);
+  let BaseClass;
+
+  suiteSetup(function() {
+    BaseClass = class extends Polymer.PropertyEffects(HTMLElement) {
+      connectedCallback() {
+        this.pcSpy = sinon.spy();
+        this._flushProperties();
+      }
+      _propertiesChanged(props, changedProps, oldProps) {
+        this.pcSpy(props, changedProps, oldProps);
+        super._propertiesChanged(props, changedProps, oldProps);
+      }
     }
-  }
+  });
 
   test('generic property effect', function() {
     class TestClass extends BaseClass {