diff --git a/src/core/__tests__/ReactMountDestruction-test.js b/src/core/__tests__/ReactMountDestruction-test.js
index e476dd0864b..a654f496780 100644
--- a/src/core/__tests__/ReactMountDestruction-test.js
+++ b/src/core/__tests__/ReactMountDestruction-test.js
@@ -43,17 +43,17 @@ describe('ReactMount', function() {
     React.renderComponent(instanceTwo, secondRootDiv);
 
     // Test that two react roots are rendered in isolation
-    expect(firstRootDiv.getElementsByClassName('firstReactDiv').length)
+    expect(firstRootDiv.querySelectorAll('.firstReactDiv').length)
       .toBe(1);
-    expect(secondRootDiv.getElementsByClassName('secondReactDiv').length)
+    expect(secondRootDiv.querySelectorAll('.secondReactDiv').length)
       .toBe(1);
 
     // Test that after unmounting each, they are no longer in the document.
     React.unmountComponentAtNode(firstRootDiv);
-    expect(firstRootDiv.getElementsByClassName('firstReactDiv').length)
+    expect(firstRootDiv.querySelectorAll('.firstReactDiv').length)
       .toBe(0);
     React.unmountComponentAtNode(secondRootDiv);
-    expect(secondRootDiv.getElementsByClassName('secondReactDiv').length)
+    expect(secondRootDiv.querySelectorAll('.secondReactDiv').length)
       .toBe(0);
   });
 });