diff --git a/.gitignore b/.gitignore
index bebf306..01fbb46 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,4 +7,4 @@ dist/
 .idea/
 .DS_Store
 Thumbs.db
-coverage/
\ No newline at end of file
+coverage/.worktrees/
diff --git a/test/render-rerenderable.test.ts b/test/render-rerenderable.test.ts
index 8888525..feec7c1 100644
--- a/test/render-rerenderable.test.ts
+++ b/test/render-rerenderable.test.ts
@@ -81,15 +81,15 @@ describe("Root.render() re-renderable", () => {
     expect(divFiber.props.class).toBe("b");
   });
 
-  it("prepareUpdate is called for changed props on re-render", () => {
-    const { host, prepareUpdateCalls } = makeHost();
+  it("commitUpdate is called for changed props on re-render", () => {
+    const { host, commitUpdateCalls } = makeHost();
     const root = createHostRoot(host, {});
     root.render(h("div", { class: "old" }, "hello"));
-    prepareUpdateCalls.length = 0;
+    commitUpdateCalls.length = 0;
 
     root.render(h("div", { class: "new" }, "hello"));
-    expect(prepareUpdateCalls.length).toBeGreaterThanOrEqual(1);
-    const divCall = prepareUpdateCalls.find((c) => c.tag === "div");
+    expect(commitUpdateCalls.length).toBeGreaterThanOrEqual(1);
+    const divCall = commitUpdateCalls.find((c) => c.tag === "div");
     expect(divCall).toBeDefined();
     expect(divCall!.prevProps.class).toBe("old");
     expect(divCall!.nextProps.class).toBe("new");
diff --git a/test/signal-driven-updates.test.ts b/test/signal-driven-updates.test.ts
index d2d60f9..b0a2761 100644
--- a/test/signal-driven-updates.test.ts
+++ b/test/signal-driven-updates.test.ts
@@ -60,8 +60,8 @@ describe("signal-driven-updates", () => {
   });
 
   describe("wireSignalToFiber", () => {
-    it("signal change triggers prepareUpdate + commitUpdate", async () => {
-      const { host, prepareUpdateCalls, commitUpdateCalls } = makeTrackingHost();
+    it("signal change triggers commitUpdate", async () => {
+      const { host, commitUpdateCalls } = makeTrackingHost();
       const color = signal("red");
 
       const root = createHostRoot(host, {});
@@ -77,8 +77,7 @@ describe("signal-driven-updates", () => {
         {},
       );
 
-      expect(prepareUpdateCalls.length).toBe(0);
-      expect(commitUpdateCalls.length).toBe(0);
+      commitUpdateCalls.length = 0;
 
       color.value = "blue";
 
@@ -86,16 +85,9 @@ describe("signal-driven-updates", () => {
         queueMicrotask(() => resolve());
       });
 
-      expect(prepareUpdateCalls.length).toBeGreaterThanOrEqual(1);
-      const lastPrepare = prepareUpdateCalls[prepareUpdateCalls.length - 1]!;
-      expect(lastPrepare.tag).toBe("div");
-      expect(lastPrepare.prevProps.color).toBe("red");
-      expect(lastPrepare.nextProps.color).toBe("blue");
-
       expect(commitUpdateCalls.length).toBeGreaterThanOrEqual(1);
       const lastCommit = commitUpdateCalls[commitUpdateCalls.length - 1]!;
       expect(lastCommit.instance).toBe(divFiber.instance);
-      expect(lastCommit.payload).toEqual({ color: "blue" });
     });
 
     it("signal effect disposer stored in fiber.signalDisposers", () => {
@@ -120,7 +112,7 @@ describe("signal-driven-updates", () => {
     });
 
     it("disposing signal via signalDisposers stops updates", async () => {
-      const { host, prepareUpdateCalls } = makeTrackingHost();
+      const { host, commitUpdateCalls } = makeTrackingHost();
       const color = signal("red");
 
       const root = createHostRoot(host, {});
@@ -142,20 +134,20 @@ describe("signal-driven-updates", () => {
       const disposer = divFiber.signalDisposers.pop()!;
       disposer();
 
-      const callCountBefore = prepareUpdateCalls.filter((c) => c.tag === "div").length;
+      const callCountBefore = commitUpdateCalls.filter((c) => c.tag === "div").length;
       color.value = "green";
 
       await new Promise<void>((resolve) => {
         queueMicrotask(() => resolve());
       });
 
-      expect(prepareUpdateCalls.filter((c) => c.tag === "div").length).toBe(callCountBefore);
+      expect(commitUpdateCalls.filter((c) => c.tag === "div").length).toBe(callCountBefore);
     });
   });
 
   describe("batch of signal changes", () => {
     it("batch of signal changes results in single reconciliation pass", async () => {
-      const { host, prepareUpdateCalls, commitUpdateCalls } = makeTrackingHost();
+      const { host, commitUpdateCalls } = makeTrackingHost();
       const color = signal("red");
       const size = signal("small");
 
@@ -175,7 +167,6 @@ describe("signal-driven-updates", () => {
         queueMicrotask(() => resolve());
       });
       resetUpdateQueue();
-      prepareUpdateCalls.length = 0;
       commitUpdateCalls.length = 0;
 
       batch(() => {
@@ -187,14 +178,13 @@ describe("signal-driven-updates", () => {
         queueMicrotask(() => resolve());
       });
 
-      expect(prepareUpdateCalls.filter((c) => c.tag === "div").length).toBe(1);
       expect(commitUpdateCalls.filter((c) => c.tag === "div").length).toBe(1);
     });
   });
 
   describe("render() re-renderable", () => {
     it("second render reconciles props against existing fiber tree", () => {
-      const { host, prepareUpdateCalls, commitUpdateCalls, instances } = makeTrackingHost();
+      const { host, commitUpdateCalls, instances } = makeTrackingHost();
       const root = createHostRoot(host, {});
       root.render(h("div", { color: "red" }, "hello"));
 
@@ -205,14 +195,10 @@ describe("signal-driven-updates", () => {
 
       expect(instances.length).toBe(instanceCountBefore);
 
-      const divPrepareCalls = prepareUpdateCalls.filter((c) => c.tag === "div");
-      expect(divPrepareCalls.length).toBe(1);
-      expect(divPrepareCalls[0]!.prevProps.color).toBe("red");
-      expect(divPrepareCalls[0]!.nextProps.color).toBe("blue");
-
       const divCommitCalls = commitUpdateCalls.filter((c) => c.tag === "div");
       expect(divCommitCalls.length).toBe(1);
-      expect(divCommitCalls[0]!.payload).toEqual({ color: "blue" });
+      expect(divCommitCalls[0]!.prevProps.color).toBe("red");
+      expect(divCommitCalls[0]!.nextProps.color).toBe("blue");
     });
 
     it("second render does not create duplicate instances", () => {
@@ -225,16 +211,16 @@ describe("signal-driven-updates", () => {
       expect(instances.length).toBe(1);
     });
 
-    it("prepareUpdate is called for changed props on re-render", () => {
-      const { host, prepareUpdateCalls } = makeTrackingHost();
+    it("commitUpdate is called for changed props on re-render", () => {
+      const { host, commitUpdateCalls } = makeTrackingHost();
       const root = createHostRoot(host, {});
       root.render(h("span", { label: "a" }));
       root.render(h("span", { label: "b" }));
 
-      const spanPrepares = prepareUpdateCalls.filter((c) => c.tag === "span");
-      expect(spanPrepares.length).toBe(1);
-      expect(spanPrepares[0]!.prevProps.label).toBe("a");
-      expect(spanPrepares[0]!.nextProps.label).toBe("b");
+      const spanCommits = commitUpdateCalls.filter((c) => c.tag === "span");
+      expect(spanCommits.length).toBe(1);
+      expect(spanCommits[0]!.prevProps.label).toBe("a");
+      expect(spanCommits[0]!.nextProps.label).toBe("b");
     });
   });
 
diff --git a/test/value-equal-bailout.test.ts b/test/value-equal-bailout.test.ts
index 3160121..b4f28fd 100644
--- a/test/value-equal-bailout.test.ts
+++ b/test/value-equal-bailout.test.ts
@@ -88,33 +88,33 @@ describe("Value.Equal bail-out", () => {
     });
   });
 
-  describe("changed prop still triggers prepareUpdate", () => {
-    it("changed prop on parent triggers prepareUpdate", () => {
-      const { host, prepareUpdateCalls } = makeTrackingHost();
+  describe("changed prop still triggers update", () => {
+    it("changed prop on parent triggers commitUpdate", () => {
+      const { host, commitUpdateCalls } = makeTrackingHost();
       const root = createHostRoot(host, {});
       root.render(h("div", { color: "red" }));
 
-      prepareUpdateCalls.length = 0;
+      commitUpdateCalls.length = 0;
 
       root.render(h("div", { color: "blue" }));
 
-      expect(prepareUpdateCalls.length).toBeGreaterThanOrEqual(1);
-      const divCall = prepareUpdateCalls.find((c) => c.tag === "div");
+      expect(commitUpdateCalls.length).toBeGreaterThanOrEqual(1);
+      const divCall = commitUpdateCalls.find((c) => c.tag === "div");
       expect(divCall).toBeDefined();
       expect(divCall!.prevProps.color).toBe("red");
       expect(divCall!.nextProps.color).toBe("blue");
     });
 
-    it("changed child prop triggers prepareUpdate only for child", () => {
-      const { host, prepareUpdateCalls } = makeTrackingHost();
+    it("changed child prop triggers commitUpdate only for child", () => {
+      const { host, commitUpdateCalls } = makeTrackingHost();
       const root = createHostRoot(host, {});
       root.render(h("div", { color: "red" }, h("span", { label: "a" })));
 
-      prepareUpdateCalls.length = 0;
+      commitUpdateCalls.length = 0;
 
       root.render(h("div", { color: "red" }, h("span", { label: "b" })));
 
-      const spanCalls = prepareUpdateCalls.filter((c) => c.tag === "span");
+      const spanCalls = commitUpdateCalls.filter((c) => c.tag === "span");
       expect(spanCalls.length).toBe(1);
       expect(spanCalls[0]!.prevProps.label).toBe("a");
       expect(spanCalls[0]!.nextProps.label).toBe("b");
@@ -214,17 +214,17 @@ describe("Value.Equal bail-out", () => {
       expect(divFiber.effect).toBeNull();
     });
 
-    it("reconcileProps with changed node calls prepareUpdate", () => {
-      const { host, prepareUpdateCalls } = makeTrackingHost();
+    it("reconcileProps with changed node produces an update effect", () => {
+      const { host } = makeTrackingHost();
       const root = createHostRoot(host, {});
       root.render(h("div", { color: "red" }));
 
       const divFiber = root.rootFiber!.children[0]!;
-      prepareUpdateCalls.length = 0;
 
       reconcileProps(divFiber, h("div", { color: "blue" }), host as HostConfig<string, string, unknown>, {});
 
-      expect(prepareUpdateCalls.length).toBe(1);
+      expect(divFiber.effect).not.toBeNull();
+      expect(divFiber.props.color).toBe("blue");
     });
   });