diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6f5da22fe4..1997c73d8a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 
 ### Fixed
 
+- Use the same `COOLIFY_BRANCH` value in all parts of a preview deployment: `pull/<pull request number>/head`. Before, a variable that refers to `${COOLIFY_BRANCH}` got the branch of the application (for example `main`), but the container got `pull/<number>/head`. Other build packs got `pull/<number>/head:pr-<number>-coolify`, and applications from a public repository got the branch of the application ([#9572](https://github.com/coollabsio/coolify/issues/9572))
 - Send the **Resource status changes** notification when an application, preview, service, or database stops unexpectedly, for example after a crash or `docker kill`. Before, Coolify sent this notification only when it restarted the proxy or a database TCP proxy. Coolify waits 2 minutes and sends the notification only when the resource is still stopped, so a container that Docker restarts, or a deployment that replaces it, sends none. A stop, restart, or redeploy from Coolify sends no notification, and the same resource sends at most one notification in 15 minutes ([#9493](https://github.com/coollabsio/coolify/issues/9493))
 - Fix the "Network error" when you sign in with email in AppFlowy Web. AppFlowy Web runs on its own domain and sends a `Redirect_to` header to GoTrue on the admin domain, and GoTrue blocked the CORS preflight because it did not allow that header. The AppFlowy service template now sets `GOTRUE_CORS_ALLOWED_HEADERS=redirect_to`. For an existing AppFlowy service, add this variable to the `gotrue` service in the Docker Compose file and restart the service ([#10545](https://github.com/coollabsio/coolify/issues/10545))
 - List the commit images of Docker Compose applications on the **Rollback** page and in `GET /api/v1/applications/{uuid}/rollback-images`. Since v4.5.0 the list was always empty, because a Compose build names each service image `<uuid>_<service>`. The page also shows the running commit when the Compose file has services from other images, for example a database ([#12446](https://github.com/coollabsio/coolify/issues/12446))
diff --git a/app/Jobs/ApplicationDeploymentJob.php b/app/Jobs/ApplicationDeploymentJob.php
index 25dca2348b..d0b45e4f18 100644
--- a/app/Jobs/ApplicationDeploymentJob.php
+++ b/app/Jobs/ApplicationDeploymentJob.php
@@ -3380,8 +3380,9 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
                 }
             }
         }
-        if (isset($this->application->git_branch)) {
-            $this->coolify_variables .= 'COOLIFY_BRANCH='.escapeShellValue($this->application->git_branch).' ';
+        $branch = $this->application->coolifyBranch($this->pull_request_id);
+        if (isset($branch)) {
+            $this->coolify_variables .= 'COOLIFY_BRANCH='.escapeShellValue($branch).' ';
         }
         $this->coolify_variables .= 'COOLIFY_RESOURCE_UUID='.escapeShellValue($this->application->uuid).' ';
     }
@@ -4298,7 +4299,7 @@ COPY ./nginx.conf /etc/nginx/conf.d/default.conf");
     protected function generate_coolify_env_variables(bool $forBuildTime = false): Collection
     {
         $coolify_envs = collect([]);
-        $local_branch = $this->branch;
+        $local_branch = $this->application->coolifyBranch($this->pull_request_id);
         if ($this->pull_request_id !== 0) {
             // Only add SOURCE_COMMIT for runtime OR when explicitly enabled for build-time
             // SOURCE_COMMIT changes with each commit and breaks Docker cache if included in build
diff --git a/app/Models/Application.php b/app/Models/Application.php
index 96d7389471..a21d8de6ea 100644
--- a/app/Models/Application.php
+++ b/app/Models/Application.php
@@ -1962,6 +1962,18 @@ class Application extends BaseModel
         return $commands;
     }
 
+    /**
+     * The COOLIFY_BRANCH value of a deployment. Preview deployments use the pull request ref.
+     */
+    public function coolifyBranch(int $pullRequestId = 0): ?string
+    {
+        if ($pullRequestId !== 0) {
+            return "pull/{$pullRequestId}/head";
+        }
+
+        return $this->git_branch;
+    }
+
     public function generateGitImportCommands(string $deployment_uuid, int $pull_request_id = 0, ?string $git_type = null, bool $exec_in_docker = true, bool $only_checkout = false, ?string $custom_base_dir = null, ?string $commit = null)
     {
         $branch = $this->git_branch;
diff --git a/bootstrap/helpers/parsers.php b/bootstrap/helpers/parsers.php
index b723993b67..14b9638432 100644
--- a/bootstrap/helpers/parsers.php
+++ b/bootstrap/helpers/parsers.php
@@ -2002,10 +2002,7 @@ function applicationParser(Application $resource, int $pull_request_id = 0, ?int
                 }
             }
         }
-        $branch = $originalResource->git_branch;
-        if ($pullRequestId !== 0) {
-            $branch = "pull/{$pullRequestId}/head";
-        }
+        $branch = $originalResource->coolifyBranch($pullRequestId);
         if ($originalResource->environment_variables->where('key', 'COOLIFY_BRANCH')->isEmpty()) {
             $coolifyEnvironments->put('COOLIFY_BRANCH', "\"{$branch}\"");
         }
diff --git a/tests/Unit/ApplicationDeploymentCoolifyBranchTest.php b/tests/Unit/ApplicationDeploymentCoolifyBranchTest.php
new file mode 100644
index 0000000000..089afedb57
--- /dev/null
+++ b/tests/Unit/ApplicationDeploymentCoolifyBranchTest.php
@@ -0,0 +1,85 @@
+<?php
+
+use App\Jobs\ApplicationDeploymentJob;
+use App\Models\Application;
+use App\Models\ApplicationPreview;
+use App\Models\Environment;
+use App\Models\Project;
+use App\Models\Server;
+use App\Models\StandaloneDocker;
+use App\Models\Team;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+uses(TestCase::class, RefreshDatabase::class);
+
+class TestableCoolifyBranchDeploymentJob extends ApplicationDeploymentJob
+{
+    public function __construct() {}
+
+    public function execute_remote_command(...$commands): void {}
+}
+
+/**
+ * @return array{shell: string, env: array<string, mixed>}
+ */
+function coolifyBranchVariables(string $buildPack, int $pullRequestId, string $checkedOutBranch): array
+{
+    $team = Team::create(['name' => 'Branch Team', 'personal_team' => false, 'show_boarding' => false]);
+    $project = Project::create(['name' => 'Branch Project', 'team_id' => $team->id]);
+    $environment = Environment::where('project_id', $project->id)->firstOrFail();
+    $server = Server::factory()->create(['team_id' => $team->id]);
+    $application = Application::factory()->create([
+        'environment_id' => $environment->id,
+        'destination_id' => $server->standaloneDockers()->firstOrFail()->id,
+        'destination_type' => StandaloneDocker::class,
+        'build_pack' => $buildPack,
+        'git_branch' => 'main',
+    ]);
+    $preview = $pullRequestId === 0 ? null : ApplicationPreview::create([
+        'application_id' => $application->id,
+        'pull_request_id' => $pullRequestId,
+        'pull_request_html_url' => 'https://github.com/coollabsio/example/pull/'.$pullRequestId,
+        'fqdn' => 'https://pr.example.com',
+    ]);
+
+    $job = new TestableCoolifyBranchDeploymentJob;
+    $reflection = new ReflectionClass(ApplicationDeploymentJob::class);
+
+    foreach ([
+        'application' => $application->fresh(),
+        'pull_request_id' => $pullRequestId,
+        'preview' => $preview,
+        'commit' => 'HEAD',
+        'branch' => $checkedOutBranch,
+    ] as $property => $value) {
+        $reflection->getProperty($property)->setValue($job, $value);
+    }
+
+    $reflection->getMethod('set_coolify_variables')->invoke($job);
+
+    return [
+        'shell' => $reflection->getProperty('coolify_variables')->getValue($job),
+        'env' => $reflection->getMethod('generate_coolify_env_variables')->invoke($job, true)->all(),
+    ];
+}
+
+it('uses the pull request ref for COOLIFY_BRANCH in compose variables of a preview deployment', function () {
+    $variables = coolifyBranchVariables('dockercompose', 7, 'main');
+
+    expect($variables['shell'])->toContain("COOLIFY_BRANCH='pull/7/head'");
+});
+
+it('uses the pull request ref for COOLIFY_BRANCH in env variables of a preview deployment', function () {
+    $variables = coolifyBranchVariables('dockerfile', 7, 'pull/7/head:pr-7-coolify');
+
+    expect($variables['env']['COOLIFY_BRANCH'])->toBe('pull/7/head')
+        ->and($variables['shell'])->toContain("COOLIFY_BRANCH='pull/7/head'");
+});
+
+it('uses the application branch for COOLIFY_BRANCH of a production deployment', function () {
+    $variables = coolifyBranchVariables('dockerfile', 0, 'main');
+
+    expect($variables['env']['COOLIFY_BRANCH'])->toBe('main')
+        ->and($variables['shell'])->toContain("COOLIFY_BRANCH='main'");
+});