diff --git a/app/Jobs/ApplicationDeploymentJob.php b/app/Jobs/ApplicationDeploymentJob.php
index 70931ece2e..a502ef7dc1 100644
--- a/app/Jobs/ApplicationDeploymentJob.php
+++ b/app/Jobs/ApplicationDeploymentJob.php
@@ -38,6 +38,7 @@ use Illuminate\Foundation\Bus\Dispatchable;
 use Illuminate\Queue\InteractsWithQueue;
 use Illuminate\Queue\SerializesModels;
 use Illuminate\Queue\TimeoutExceededException;
+use Illuminate\Support\Arr;
 use Illuminate\Support\Collection;
 use Illuminate\Support\Facades\Cache;
 use Illuminate\Support\Sleep;
@@ -919,7 +920,8 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
         $this->application_deployment_queue->addLogEntry('Pulling & building required images.');
 
         // Save build-time .env file BEFORE the build
-        $this->save_buildtime_environment_variables($buildEnvironment);
+        $buildEnvironment ??= $this->generate_buildtime_environment_variables();
+        $this->save_buildtime_environment_variables($buildEnvironment->merge($this->compose_build_interpolation_variables($composeFile, $buildEnvironment)));
 
         if ($this->docker_compose_custom_build_command) {
             // Auto-inject -f (compose file) and --env-file flags using helper function
@@ -985,6 +987,46 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
         }
     }
 
+    /**
+     * `docker compose build` interpolates the whole Compose file, so a required runtime-only variable
+     * (`${KEY:?}` in `environment:`) fails the build when the build-time .env file does not define it.
+     * This gives the build the runtime .env lines of the variables that the file uses outside its build
+     * sections. A variable that a build section or a build secret can read is left out, so a
+     * runtime-only value never becomes a build argument or part of an image.
+     *
+     * @return Collection<int, string>
+     */
+    private function compose_build_interpolation_variables(mixed $composeFile, Collection $buildEnvironment): Collection
+    {
+        $compose = is_string($composeFile) ? parseDockerComposeYaml($composeFile) : convertToArray($composeFile);
+        $references = fn (array $values): Collection => collect(Arr::flatten($values))
+            ->flatMap(fn (mixed $value): Collection => extractDockerComposeEnvironmentVariableReferences($value));
+
+        $readByBuilds = collect(data_get($compose, 'secrets', []))->pluck('environment')->filter();
+        foreach (data_get($compose, 'services', []) as $serviceName => $service) {
+            $build = data_get($service, 'build');
+            if ($build === null) {
+                continue;
+            }
+            $args = data_get($build, 'args', []);
+            $argNames = is_array($args) && array_is_list($args)
+                ? array_map(fn (mixed $arg): string => explode('=', (string) $arg, 2)[0], $args)
+                : array_keys((array) $args);
+            $readByBuilds = $readByBuilds->merge($argNames)->merge($references((array) $build));
+            unset($compose['services'][$serviceName]['build']);
+        }
+
+        $buildKeys = $buildEnvironment->map(fn (string $line): string => explode('=', $line, 2)[0]);
+        $keys = $references($compose)->unique()->diff($readByBuilds)->diff($buildKeys);
+        if ($keys->isEmpty()) {
+            return collect();
+        }
+
+        return $this->generate_runtime_environment_variables()
+            ->filter(fn (string $line): bool => $keys->contains(explode('=', $line, 2)[0]))
+            ->values();
+    }
+
     /**
      * Parses the Compose file for this deployment and writes the volume warnings of the parser
      * (for example an external volume that the resource does not use yet) to the deployment log.
diff --git a/tests/Feature/ApplicationDeploymentControlVarFilteringTest.php b/tests/Feature/ApplicationDeploymentControlVarFilteringTest.php
index 4abe239679..3d6707505f 100644
--- a/tests/Feature/ApplicationDeploymentControlVarFilteringTest.php
+++ b/tests/Feature/ApplicationDeploymentControlVarFilteringTest.php
@@ -2076,3 +2076,70 @@ it('gives a preview from before v4.5.1 the production values it had', function (
     expect($runtimeEnvs->contains(fn (string $env) => str($env)->startsWith('DB_PASSWORD=') && str($env)->contains('production-secret')))->toBeTrue()
         ->and($runtimeEnvs->contains(fn (string $env) => str($env)->startsWith('APP_NAME=') && str($env)->contains('coolify')))->toBeTrue();
 });
+
+it('lets the Compose build interpolate runtime-only variables without passing them to the build', function (int $pullRequestId) {
+    $compose = <<<'YAML'
+services:
+  app:
+    build:
+      context: .
+      args:
+        MAPPED_ARG: '${RUNTIME_IN_BUILD_ARGS}'
+        LISTED_FROM_ENV: null
+    environment:
+      FERNET_KEY: '${FERNET_KEY:?}'
+      OPTIONAL_REQUIRED: '${OPTIONAL_REQUIRED?}'
+      BUILD_VALUE: '${BUILD_VALUE}'
+  worker:
+    build:
+      context: ./worker
+      args:
+        - LISTED_ARG
+    environment:
+      FERNET_KEY: '${FERNET_KEY:?}'
+YAML;
+
+    [$application, $server] = makeDeploymentControlVarFixture([
+        'build_pack' => 'dockercompose',
+        'docker_compose_raw' => $compose,
+        'docker_compose' => $compose,
+        'docker_compose_domains' => '[]',
+    ]);
+    $application->settings()->update(['inject_build_args_to_dockerfile' => false]);
+
+    createApplicationEnvironmentVariable($application, ['key' => 'FERNET_KEY', 'value' => 'runtime-fernet-key', 'is_buildtime' => false]);
+    createApplicationEnvironmentVariable($application, ['key' => 'OPTIONAL_REQUIRED', 'value' => '', 'is_buildtime' => false]);
+    createApplicationEnvironmentVariable($application, ['key' => 'RUNTIME_IN_BUILD_ARGS', 'value' => 'runtime-mapped-arg', 'is_buildtime' => false]);
+    createApplicationEnvironmentVariable($application, ['key' => 'LISTED_FROM_ENV', 'value' => 'runtime-null-arg', 'is_buildtime' => false]);
+    createApplicationEnvironmentVariable($application, ['key' => 'LISTED_ARG', 'value' => 'runtime-listed-arg', 'is_buildtime' => false]);
+    createApplicationEnvironmentVariable($application, ['key' => 'BUILD_VALUE', 'value' => 'build-value']);
+
+    [$job, $reflection] = makeControlVarFilteringJob($application->fresh(), $server, [
+        'pull_request_id' => $pullRequestId,
+        'remote_secrets_cache' => [],
+        'force_rebuild' => false,
+        'docker_compose_location' => '/docker-compose.yaml',
+    ]);
+
+    invokeDeploymentJobMethod($job, $reflection, 'generate_build_env_variables');
+    $buildEnvironment = invokeDeploymentJobMethod($job, $reflection, 'generate_buildtime_environment_variables');
+    invokeDeploymentJobMethod($job, $reflection, 'build_docker_compose_images', parseDockerComposeYaml($compose), $buildEnvironment);
+
+    $buildEnvFile = $job->writtenArtifacts[ApplicationDeploymentJob::BUILD_TIME_ENV_PATH];
+    $buildCommand = collect($job->recordedCommands)->flatten()->first(fn (mixed $command): bool => is_string($command) && str_contains($command, ' build --pull'));
+    $buildArgs = readDeploymentJobProperty($job, $reflection, 'build_args')->implode(' ');
+
+    expect($buildEnvFile)->toContain('FERNET_KEY="runtime-fernet-key"')
+        ->toContain('OPTIONAL_REQUIRED=""')
+        ->toContain('BUILD_VALUE=')
+        ->not->toContain('runtime-mapped-arg')
+        ->not->toContain('runtime-null-arg')
+        ->not->toContain('runtime-listed-arg')
+        ->and($buildCommand)->toContain('--env-file '.ApplicationDeploymentJob::BUILD_TIME_ENV_PATH)
+        ->and($buildArgs)->toContain('BUILD_VALUE')
+        ->not->toContain('FERNET_KEY')
+        ->not->toContain('runtime-');
+})->with([
+    'production' => 0,
+    'preview' => 42,
+]);