diff --git a/tests/unit/transform-foundation.integration.test.tsx b/tests/unit/transform-foundation.integration.test.tsx
index b13a42c5..df252fe8 100644
--- a/tests/unit/transform-foundation.integration.test.tsx
+++ b/tests/unit/transform-foundation.integration.test.tsx
@@ -10,6 +10,7 @@ import type { ActiveTransformSession, TransformSessionState } from "../../src/co
 import { createBoxBrush } from "../../src/document/brushes";
 import { createEmptySceneDocument } from "../../src/document/scene-document";
 import { createPlayerStartEntity } from "../../src/entities/entity-instances";
+import type { ViewportPanelCameraState } from "../../src/viewport-three/viewport-layout";
 
 const { MockViewportHost, viewportHostInstances } = vi.hoisted(() => {
   const viewportHostInstances: Array<{
@@ -249,6 +250,18 @@ function commitTransform(viewportHost: ReturnType<typeof getTopLeftViewportHost>
   });
 }
 
+function emitCameraStateChange(viewportHost: ReturnType<typeof getTopLeftViewportHost>, cameraState: ViewportPanelCameraState) {
+  const handler = viewportHost.setCameraStateChangeHandler.mock.calls.at(-1)?.[0] as ((cameraState: ViewportPanelCameraState) => void) | undefined;
+
+  if (handler === undefined) {
+    throw new Error("Camera state change handler was not registered.");
+  }
+
+  act(() => {
+    handler(cameraState);
+  });
+}
+
 describe("transform foundation integration", () => {
   beforeEach(() => {
     viewportHostInstances.length = 0;