diff --git a/.github/workflows/cleanup-preview-env.yaml b/.github/workflows/cleanup-preview-env.yaml
new file mode 100644
index 00000000..bc513202
--- /dev/null
+++ b/.github/workflows/cleanup-preview-env.yaml
@@ -0,0 +1,41 @@
+name: Cleanup preview environment
+
+on:
+  pull_request:
+    types: [closed]
+
+permissions:
+  deployments: write
+
+jobs:
+  cleanup:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Delete preview environment
+        uses: actions/github-script@v8
+        with:
+          script: |
+            const environment = `preview-pr-${context.payload.pull_request.number}`;
+
+            // Deactivate all deployments for this environment first
+            const deployments = await github.rest.repos.listDeployments({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              environment
+            });
+
+            for (const deployment of deployments.data) {
+              await github.rest.repos.createDeploymentStatus({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                deployment_id: deployment.id,
+                state: 'inactive'
+              });
+            }
+
+            // Delete the environment
+            await github.rest.repos.deleteAnEnvironment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              environment_name: environment
+            });
diff --git a/.github/workflows/cloudflare-pages.yaml b/.github/workflows/cloudflare-pages.yaml
index 93872b98..2bee63fa 100644
--- a/.github/workflows/cloudflare-pages.yaml
+++ b/.github/workflows/cloudflare-pages.yaml
@@ -48,7 +48,7 @@ jobs:
           script: |
             const isPR = context.eventName === 'pull_request';
             const sha = isPR ? context.payload.pull_request.head.sha : context.sha;
-            const environment = isPR ? 'preview' : 'production';
+            const environment = isPR ? `preview-pr-${context.payload.pull_request.number}` : 'production';
             const deploymentUrl = '${{ steps.deploy.outputs.deployment-url }}';
 
             // GitHub deployment (shows in PR UI)
@@ -58,7 +58,8 @@ jobs:
               ref: sha,
               environment,
               auto_merge: false,
-              required_contexts: []
+              required_contexts: [],
+              transient_environment: isPR
             });
             await github.rest.repos.createDeploymentStatus({
               owner: context.repo.owner,