diff --git a/packages/core/test/overlay/overlayTests.tsx b/packages/core/test/overlay/overlayTests.tsx
index f581d8c040..0f864bfe2c 100644
--- a/packages/core/test/overlay/overlayTests.tsx
+++ b/packages/core/test/overlay/overlayTests.tsx
@@ -200,11 +200,16 @@ describe("<Overlay>", () => {
             let buttonRef: HTMLElement;
             const focusBtnAndAssert = () => {
                 buttonRef.focus();
+                // nested setTimeouts delay execution until the next frame, not
+                // just to the end of the current frame. necessary to wait for
+                // focus to change.
                 setTimeout(() => {
-                    wrapper.update();
-                    assert.notStrictEqual(buttonRef, document.activeElement);
-                    done();
-                }, 10);
+                    setTimeout(() => {
+                        wrapper.update();
+                        assert.notStrictEqual(buttonRef, document.activeElement);
+                        done();
+                    });
+                });
             };
 
             wrapper = mount(
@@ -302,12 +307,15 @@ describe("<Overlay>", () => {
 
         function assertFocus(selector: string, done: MochaDone) {
             wrapper.update();
-            // small explicit timeout reduces flakiness of these tests,
-            // which rely on requestAnimationFrame to update focus state.
+            // the behavior being tested relies on requestAnimationFrame. to
+            // avoid flakiness, use nested setTimeouts to delay execution until
+            // the next frame, not just to the end of the current frame.
             setTimeout(() => {
-                assert.strictEqual(document.querySelector(selector), document.activeElement);
-                done();
-            }, 10);
+                setTimeout(() => {
+                    assert.strictEqual(document.querySelector(selector), document.activeElement);
+                    done();
+                });
+            });
         }
     });