diff --git a/packages/app/e2e.test.ts b/packages/app/e2e.test.ts
index 14901678..b3819313 100644
--- a/packages/app/e2e.test.ts
+++ b/packages/app/e2e.test.ts
@@ -14,11 +14,20 @@ const E2E_TEMP_DIR_PREFIX = "pkg-pr-new-e2e-";
 
 let server: Awaited<ReturnType<ReturnType<typeof simulation>["listen"]>>;
 let workerUrl: string;
-let githubOutputDir: string;
+let tempDir: string;
 let githubOutputPath: string;
 
 let worker: UnstableDevWorker;
+
+const { stdout: gitRevParseOutput } = await ezSpawn.async(
+  "git rev-parse HEAD",
+  { stdio: "overlapped" },
+);
+const gitRevParse = gitRevParseOutput.trim();
+
 beforeAll(async () => {
+  tempDir = await fs.mkdtemp(path.join(os.tmpdir(), E2E_TEMP_DIR_PREFIX));
+
   const app = simulation({
     initialState: {
       users: [],
@@ -51,15 +60,12 @@ beforeAll(async () => {
     `${import.meta.dirname}/dist/_worker.js/index.js`,
     {
       config: `${import.meta.dirname}/wrangler.toml`,
+      persistTo: path.join(tempDir, "worker"),
     },
   );
   const url = `${worker.proxyData.userWorkerUrl.protocol}//${worker.proxyData.userWorkerUrl.hostname}:${worker.proxyData.userWorkerUrl.port}`;
   workerUrl = url;
-
-  githubOutputDir = await fs.mkdtemp(
-    path.join(os.tmpdir(), E2E_TEMP_DIR_PREFIX),
-  );
-  githubOutputPath = path.join(githubOutputDir, "output");
+  githubOutputPath = path.join(tempDir, "output");
   await fs.writeFile(githubOutputPath, "");
 
   await ezSpawn.async(
@@ -74,8 +80,8 @@ beforeAll(async () => {
 
 afterAll(async () => {
   await server.ensureClose();
-  if (githubOutputDir?.includes(E2E_TEMP_DIR_PREFIX)) {
-    await fs.rm(githubOutputDir, { recursive: true, force: true });
+  if (tempDir?.includes(E2E_TEMP_DIR_PREFIX)) {
+    await fs.rm(tempDir, { recursive: true, force: true });
   }
 });
 
@@ -123,6 +129,7 @@ describe.sequential.each([
       GITHUB_SHA: payload.workflow_run.head_sha,
       GITHUB_ACTION: payload.workflow_run.id,
       GITHUB_JOB: payload.workflow_run.name,
+      GITHUB_EVENT_NAME: payload.workflow_run.event,
       GITHUB_REF_NAME: pr
         ? `${pr.payload.number}/merge`
         : payload.workflow_run.head_branch,
@@ -147,14 +154,12 @@ describe.sequential.each([
     expect(process.stderr).toContain("pkg-pr-new:");
     expect(process.stderr).toContain("playground-a:");
     expect(process.stderr).toContain("playground-b:");
-  }, 10_000);
+  }, 20_000);
 
   it(`serves and installs playground-a for ${mode}`, async () => {
     const [owner, repo] = payload.repository.full_name.split("/");
-    const { stdout: gitHeadSha } = await ezSpawn.async("git rev-parse HEAD", {
-      stdio: "overlapped",
-    });
-    const sha = gitHeadSha.trim().substring(0, 7);
+    const fullSha = pr ? payload.workflow_run.head_sha : gitRevParse;
+    const sha = fullSha.substring(0, 7);
     const ref = pr?.payload.number ?? payload.workflow_run.head_branch;
 
     // Test download with SHA
@@ -190,14 +195,12 @@ describe.sequential.each([
     expect(installProcess.stdout).toContain(
       "playground-a installed successfully!",
     );
-  }, 10_000);
+  }, 20_000);
 
   it(`serves and installs playground-b for ${mode}`, async () => {
     const [owner, repo] = payload.repository.full_name.split("/");
-    const { stdout: gitHeadSha } = await ezSpawn.async("git rev-parse HEAD", {
-      stdio: "overlapped",
-    });
-    const sha = gitHeadSha.trim().substring(0, 7);
+    const fullSha = pr ? payload.workflow_run.head_sha : gitRevParse;
+    const sha = fullSha.substring(0, 7);
 
     // Test download
     const response = await worker.fetch(
@@ -225,7 +228,7 @@ describe.sequential.each([
     expect(installProcess.stdout).toContain(
       "playground-b installed successfully!",
     );
-  }, 10_000);
+  }, 20_000);
 });
 
 describe("URL redirects", () => {
diff --git a/packages/cli/index.ts b/packages/cli/index.ts
index 885f19c7..205e632c 100644
--- a/packages/cli/index.ts
+++ b/packages/cli/index.ts
@@ -233,13 +233,24 @@ const main = defineCommand({
             process.exit(1);
           }
 
-          const { stdout: gitShaOutput } = await ezSpawn.async(
-            "git rev-parse HEAD",
-            {
-              stdio: "overlapped",
-            },
-          );
-          const sha = gitShaOutput.trim();
+          let { sha } = await checkResponse.json();
+
+          // on pull_request events, GitHub creates a virtual merge commit that doesn't
+          // actually belong to the PR, so we use the workflow's head_sha instead
+          if (process.env.GITHUB_EVENT_NAME !== "pull_request") {
+            try {
+              const { stdout: gitRevParseOutput } = await ezSpawn.async(
+                "git rev-parse HEAD",
+                { stdio: "overlapped" },
+              );
+
+              sha = gitRevParseOutput.trim();
+            } catch {
+              // git rev-parse fails when the CLI runs outside a git repository
+              // (e.g. the checkout was done in a separate job and only artifacts were restored here)
+              // falling back to the workflow's head_sha from checkResponse
+            }
+          }
 
           const deps: Map<string, string> = new Map(); // pkg.pr.new versions of the package
           const realDeps: Map<string, string> | null = isPeerDepsEnabled