diff --git a/app/Http/Controllers/Webhook/Github.php b/app/Http/Controllers/Webhook/Github.php
index cecd4186d9..ac83d7ae6f 100644
--- a/app/Http/Controllers/Webhook/Github.php
+++ b/app/Http/Controllers/Webhook/Github.php
@@ -71,7 +71,6 @@ class Github extends Controller
                     'before_sha' => $before_sha,
                     'after_sha' => $after_sha,
                     'commit_sha' => $commit_sha,
-                    'author_association' => $author_association,
                     'is_fork_pull_request' => $is_fork_pull_request,
                 ] = $this->readPullRequestPayload($payload);
                 $full_name = data_get($payload, 'repository.full_name');
@@ -239,7 +238,6 @@ class Github extends Controller
                             beforeSha: $before_sha,
                             afterSha: $after_sha,
                             commitSha: $commit_sha,
-                            authorAssociation: $author_association,
                             fullName: $full_name,
                             isForkPullRequest: $is_fork_pull_request,
                         );
@@ -459,7 +457,6 @@ class Github extends Controller
                     'before_sha' => $before_sha,
                     'after_sha' => $after_sha,
                     'commit_sha' => $commit_sha,
-                    'author_association' => $author_association,
                     'is_fork_pull_request' => $is_fork_pull_request,
                 ] = $this->readPullRequestPayload($payload);
                 $full_name = $this->manualWebhookRepositoryFullName(data_get($payload, 'repository.full_name'));
@@ -601,7 +598,6 @@ class Github extends Controller
                             beforeSha: $before_sha,
                             afterSha: $after_sha,
                             commitSha: $commit_sha,
-                            authorAssociation: $author_association,
                             fullName: $full_name,
                             isForkPullRequest: $is_fork_pull_request,
                         );
@@ -655,7 +651,7 @@ class Github extends Controller
     /**
      * Read and validate the pull_request payload fields that the handlers use.
      *
-     * @return array{action: string, pull_request_id: int, pull_request_html_url: string, pull_request_title: ?string, branch: ?string, base_branch: ?string, before_sha: ?string, after_sha: ?string, commit_sha: string, author_association: ?string, is_fork_pull_request: bool}
+     * @return array{action: string, pull_request_id: int, pull_request_html_url: string, pull_request_title: ?string, branch: ?string, base_branch: ?string, before_sha: ?string, after_sha: ?string, commit_sha: string, is_fork_pull_request: bool}
      *
      * @throws InvalidWebhookPayloadException When a field has a wrong type or format.
      */
@@ -673,7 +669,6 @@ class Github extends Controller
             'before_sha' => $this->webhookCommitSha($payload, 'before'),
             'after_sha' => $this->webhookCommitSha($payload, 'after') ?? $head_sha,
             'commit_sha' => $head_sha ?? 'HEAD',
-            'author_association' => $this->webhookPayloadString($payload, 'pull_request.author_association'),
             'is_fork_pull_request' => $this->isForkPullRequest($payload),
         ];
     }
@@ -681,13 +676,15 @@ class Github extends Controller
     /**
      * Determine whether a pull_request webhook payload originates from a fork.
      *
-     * GitHub's `author_association` is not a reliable trust signal (it grants
-     * CONTRIBUTOR to anyone who has merely opened an issue/PR before), so fork
-     * detection is gated on whether the PR crosses repository boundaries.
+     * A same-repository PR branch can only be pushed by users with write access,
+     * so this is the trust signal for preview deployments. GitHub's
+     * `author_association` is not reliable for this: users with access through a
+     * team or a private organization membership arrive as CONTRIBUTOR or NONE.
      *
      * The repository id comparison is the canonical signal; the `head.repo.fork`
      * flag and a case-insensitive full_name comparison are fallbacks for payloads
-     * where the ids are unavailable (e.g. a deleted head repository).
+     * where the ids are unavailable. A PR whose head repository is unknown (e.g.
+     * a deleted fork) is treated as a fork.
      *
      * @throws InvalidWebhookPayloadException When a repository id is not a positive integer.
      */
@@ -711,7 +708,7 @@ class Github extends Controller
             return Str::lower($headRepoFullName) !== Str::lower($baseRepoFullName);
         }
 
-        return false;
+        return true;
     }
 
     public function redirect(Request $request)
diff --git a/app/Jobs/ProcessGithubPullRequestWebhook.php b/app/Jobs/ProcessGithubPullRequestWebhook.php
index 8abef9a486..1602b576a2 100644
--- a/app/Jobs/ProcessGithubPullRequestWebhook.php
+++ b/app/Jobs/ProcessGithubPullRequestWebhook.php
@@ -38,7 +38,6 @@ class ProcessGithubPullRequestWebhook implements ShouldBeEncrypted, ShouldQueue
         public ?string $beforeSha,
         public ?string $afterSha,
         public string $commitSha,
-        public ?string $authorAssociation,
         public string $fullName,
         public bool $isForkPullRequest = false,
     ) {
@@ -110,22 +109,16 @@ class ProcessGithubPullRequestWebhook implements ShouldBeEncrypted, ShouldQueue
             return;
         }
 
-        // Check if PR deployments from public contributors are restricted
-        if (! $application->settings->is_pr_deployments_public_enabled) {
-            // Fork PRs carry untrusted code from a repository outside our control.
-            // GitHub's author_association cannot be trusted to gate these (it grants
-            // CONTRIBUTOR to anyone who has merely opened an issue/PR before), so fork
-            // PRs are never deployed automatically when public previews are off.
-            if ($this->isForkPullRequest) {
-                return;
-            }
+        // Fork PRs carry untrusted code, so they deploy only when public previews are on.
+        // Same-repository branches can only be pushed by users with write access.
+        if ($this->isForkPullRequest && ! $application->settings->is_pr_deployments_public_enabled) {
+            Log::info('Skipped GitHub pull request preview deployment from a fork because public PR deployments are disabled.', [
+                'application_uuid' => $application->uuid,
+                'pull_request_id' => $this->pullRequestId,
+                'action' => $this->action,
+            ]);
 
-            // Same-repo (non-fork) branch PRs require push access to the base repo,
-            // so only trusted associations are allowed to trigger a deployment.
-            $trustedAssociations = ['OWNER', 'MEMBER', 'COLLABORATOR'];
-            if (! in_array($this->authorAssociation, $trustedAssociations)) {
-                return;
-            }
+            return;
         }
 
         // Get changed files for watch path filtering (null means the full list is unknown)
diff --git a/resources/views/livewire/project/application/previews.blade.php b/resources/views/livewire/project/application/previews.blade.php
index 0792e96aa3..4abe3b4ca8 100644
--- a/resources/views/livewire/project/application/previews.blade.php
+++ b/resources/views/livewire/project/application/previews.blade.php
@@ -86,7 +86,7 @@
 
             <div class="w-full">
                 <x-forms.listbox id="isPrDeploymentsPublicEnabled" label="PR deployment access" onChange="savePreviewSettings"
-                    helper="When public, anyone can trigger PR deployments. Otherwise fork PRs are blocked and only repository owners, members, and collaborators can trigger them."
+                    helper="When public, anyone can trigger PR deployments. Otherwise only PRs from branches in the same repository are deployed and fork PRs are blocked."
                     :options="[
                         ['value' => false, 'label' => 'Repository members only'],
                         ['value' => true, 'label' => 'Public (fork PRs allowed)'],
diff --git a/tests/Feature/HorizonConfigurationTest.php b/tests/Feature/HorizonConfigurationTest.php
index 52d5742a3c..864a2f0657 100644
--- a/tests/Feature/HorizonConfigurationTest.php
+++ b/tests/Feature/HorizonConfigurationTest.php
@@ -185,7 +185,6 @@ test('webhook jobs run on the webhooks queue on cloud and on high on self-hosted
         beforeSha: null,
         afterSha: null,
         commitSha: 'abc123',
-        authorAssociation: null,
         fullName: 'coollabsio/coolify',
     );
 
diff --git a/tests/Feature/ProcessGithubPullRequestWebhookTest.php b/tests/Feature/ProcessGithubPullRequestWebhookTest.php
index 1b5c3023c1..8a5199e942 100644
--- a/tests/Feature/ProcessGithubPullRequestWebhookTest.php
+++ b/tests/Feature/ProcessGithubPullRequestWebhookTest.php
@@ -54,7 +54,7 @@ it('cleans up a closed pull request preview when pull request comment cleanup fa
             'status' => 'success',
         ]);
 
-    $job = new class(applicationId: $this->application->id, githubAppId: null, action: 'closed', pullRequestId: 42, pullRequestHtmlUrl: 'https://github.com/example/repo/pull/42', pullRequestTitle: null, beforeSha: null, afterSha: null, commitSha: 'HEAD', authorAssociation: 'OWNER', fullName: 'example/repo') extends ProcessGithubPullRequestWebhook
+    $job = new class(applicationId: $this->application->id, githubAppId: null, action: 'closed', pullRequestId: 42, pullRequestHtmlUrl: 'https://github.com/example/repo/pull/42', pullRequestTitle: null, beforeSha: null, afterSha: null, commitSha: 'HEAD', fullName: 'example/repo') extends ProcessGithubPullRequestWebhook
     {
         protected function dispatchPullRequestClosedUpdate(Application $application, ApplicationPreview $preview): void
         {
@@ -98,7 +98,6 @@ it('skips a synchronized GitHub pull request preview when the head commit messag
         beforeSha: 'before-sha',
         afterSha: 'after-sha',
         commitSha: 'after-sha',
-        authorAssociation: 'OWNER',
         fullName: 'example/repo',
     );
 
@@ -148,7 +147,6 @@ it('deploys a synchronized GitHub pull request preview when the head commit mess
         beforeSha: 'before-sha',
         afterSha: 'after-sha',
         commitSha: 'after-sha',
-        authorAssociation: 'OWNER',
         fullName: 'example/repo',
     );
 
@@ -195,7 +193,6 @@ it('skips a GitHub pull request preview when the opened or reopened head commit
         beforeSha: null,
         afterSha: null,
         commitSha: 'head-sha',
-        authorAssociation: 'OWNER',
         fullName: 'example/repo',
     );
 
@@ -246,7 +243,6 @@ it('deploys an opened GitHub pull request preview when a watched file is beyond
         beforeSha: null,
         afterSha: null,
         commitSha: 'head-sha',
-        authorAssociation: 'OWNER',
         fullName: 'example/repo',
     );
 
@@ -291,7 +287,6 @@ it('deploys a GitHub pull request preview when the full list of changed files is
         beforeSha: 'before-sha',
         afterSha: 'after-sha',
         commitSha: 'after-sha',
-        authorAssociation: 'OWNER',
         fullName: 'example/repo',
     );
 
@@ -348,7 +343,6 @@ it('skips an opened GitHub pull request preview when no changed file matches the
         beforeSha: null,
         afterSha: null,
         commitSha: 'head-sha',
-        authorAssociation: 'OWNER',
         fullName: 'example/repo',
     );
 
@@ -414,7 +408,6 @@ it('uses one GitHub App installation token for all GitHub API calls of a pull re
         beforeSha: null,
         afterSha: null,
         commitSha: 'head-sha',
-        authorAssociation: 'OWNER',
         fullName: 'example/repo',
     );
 
@@ -429,3 +422,50 @@ it('uses one GitHub App installation token for all GitHub API calls of a pull re
         ->and($repositoryRequests)->toHaveCount(3)
         ->and($repositoryRequests->every(fn (array $pair): bool => $pair[0]->hasHeader('Authorization', 'Bearer fake-installation-token')))->toBeTrue();
 });
+
+it('deploys an opened GitHub pull request preview by fork status, not by author association', function (bool $isForkPullRequest, bool $isPublicEnabled, bool $deploys) {
+    Queue::fake();
+
+    $this->application->settings->update([
+        'is_preview_deployments_enabled' => true,
+        'is_pr_deployments_public_enabled' => $isPublicEnabled,
+    ]);
+
+    Http::fake([
+        'https://api.github.com/repos/example/repo/commits/head-sha' => Http::response([
+            'commit' => ['message' => 'feat: add app'],
+        ]),
+        'https://api.github.com/repos/example/repo/pulls/42/files*' => Http::response([
+            ['filename' => 'README.md'],
+        ]),
+    ]);
+
+    $job = new ProcessGithubPullRequestWebhook(
+        applicationId: $this->application->id,
+        githubAppId: GithubApp::create([
+            'name' => 'Public GitHub',
+            'api_url' => 'https://api.github.com',
+            'html_url' => 'https://github.com',
+            'is_public' => true,
+            'team_id' => $this->team->id,
+        ])->id,
+        action: 'opened',
+        pullRequestId: 42,
+        pullRequestHtmlUrl: 'https://github.com/example/repo/pull/42',
+        pullRequestTitle: 'Add feature',
+        beforeSha: null,
+        afterSha: 'head-sha',
+        commitSha: 'head-sha',
+        fullName: 'example/repo',
+        isForkPullRequest: $isForkPullRequest,
+    );
+
+    $job->handle();
+
+    expect(ApplicationPreview::where('application_id', $this->application->id)->where('pull_request_id', 42)->exists())->toBe($deploys)
+        ->and(ApplicationDeploymentQueue::where('application_id', $this->application->id)->where('pull_request_id', 42)->exists())->toBe($deploys);
+})->with([
+    'same-repository branch with public deployments off' => [false, false, true],
+    'fork with public deployments off' => [true, false, false],
+    'fork with public deployments on' => [true, true, true],
+]);
diff --git a/tests/Feature/Webhook/WebhookPayloadTypesTest.php b/tests/Feature/Webhook/WebhookPayloadTypesTest.php
index 1ae841252e..cdc70f29fe 100644
--- a/tests/Feature/Webhook/WebhookPayloadTypesTest.php
+++ b/tests/Feature/Webhook/WebhookPayloadTypesTest.php
@@ -285,7 +285,6 @@ function webhookTypesFields(): array
             ['number', 'id', null],
             ['pull_request.html_url', 'url', null],
             ['pull_request.title', 'string', null],
-            ['pull_request.author_association', 'string', null],
             ['pull_request.head.ref', 'branch', 'No branch'],
             ['pull_request.base.ref', 'branch', 'No branch'],
             ['pull_request.head.sha', 'sha', null],
@@ -311,7 +310,6 @@ function webhookTypesFields(): array
             ['number', 'id', null],
             ['pull_request.html_url', 'url', null],
             ['pull_request.title', 'string', null],
-            ['pull_request.author_association', 'string', null],
             ['pull_request.head.ref', 'branch', 'No id or branch'],
             ['pull_request.base.ref', 'branch', 'No id or branch'],
             ['pull_request.head.sha', 'sha', null],
@@ -473,11 +471,20 @@ describe('Webhook payload value types', function () {
             && $job->pullRequestHtmlUrl === 'https://github.com/test-org/test-repo/pull/42'
             && $job->pullRequestTitle === 'Add feature'
             && $job->commitSha === webhookTypesSha()
-            && $job->authorAssociation === 'OWNER'
             && $job->fullName === 'test-org/test-repo'
             && $job->isForkPullRequest === false);
     })->with(['github manual', 'github app'])->with(['open', 'closed']);
 
+    test('a github pull request is queued as a fork when its head repository is unknown', function (string $handler) {
+        $application = webhookTypesApplication($handler);
+        $payload = webhookTypesPayload($handler, 'pr');
+        unset($payload['pull_request']['head']['repo']);
+
+        webhookTypesSend($this, $handler, 'pr', 'open', $application, $payload)->assertOk();
+
+        Queue::assertPushed(ProcessGithubPullRequestWebhook::class, fn (ProcessGithubPullRequestWebhook $job): bool => $job->isForkPullRequest === true);
+    })->with(['github manual', 'github app']);
+
     test('a github pull request with a numeric string number and sync shas is queued', function (string $handler) {
         $application = webhookTypesApplication($handler);
         $payload = webhookTypesPayload($handler, 'pr');