diff --git a/app/Http/Controllers/Api/ApplicationsController.php b/app/Http/Controllers/Api/ApplicationsController.php
index 8513dc1180..ec81538a0e 100644
--- a/app/Http/Controllers/Api/ApplicationsController.php
+++ b/app/Http/Controllers/Api/ApplicationsController.php
@@ -161,6 +161,11 @@ class ApplicationsController extends Controller
             $settings['custom_container_name_prefix'] = str($settings['custom_container_name_prefix'])->slug()->value() ?: null;
         }
 
+        // Container names use custom_internal_name only with consistent container naming, so a name sent alone turns it on.
+        if (filled($settings['custom_internal_name'] ?? null) && ! array_key_exists('is_consistent_container_name_enabled', $settings)) {
+            $settings['is_consistent_container_name_enabled'] = true;
+        }
+
         return $settings;
     }
 
@@ -184,16 +189,11 @@ class ApplicationsController extends Controller
     }
 
     /**
-     * Container names honor custom_internal_name only with consistent container naming, so reject a name that would be ignored.
+     * Container names honor custom_internal_name only with consistent container naming, so reject a name sent while the request turns it off.
      */
-    private function customInternalNameValidationResponse(array $settings, ?Application $application = null): ?JsonResponse
+    private function customInternalNameValidationResponse(array $settings): ?JsonResponse
     {
-        if (! filled($settings['custom_internal_name'] ?? null)) {
-            return null;
-        }
-        $consistentNaming = $settings['is_consistent_container_name_enabled']
-            ?? (bool) $application?->settings?->is_consistent_container_name_enabled;
-        if ($consistentNaming) {
+        if (! filled($settings['custom_internal_name'] ?? null) || ($settings['is_consistent_container_name_enabled'] ?? true)) {
             return null;
         }
 
@@ -439,7 +439,7 @@ class ApplicationsController extends Controller
                             'gpu_device_ids' => ['type' => 'string', 'nullable' => true, 'description' => 'Comma-separated GPU device IDs.'],
                             'gpu_options' => ['type' => 'string', 'nullable' => true, 'description' => 'Additional GPU options.'],
                             'is_consistent_container_name_enabled' => ['type' => 'boolean', 'description' => 'Use a consistent container name across deployments.'],
-                            'custom_internal_name' => ['type' => 'string', 'nullable' => true, 'description' => 'Custom internal container name. Requires is_consistent_container_name_enabled to be true.'],
+                            'custom_internal_name' => ['type' => 'string', 'nullable' => true, 'description' => 'Custom internal container name. Turns is_consistent_container_name_enabled on when that field is not sent; sending it as false together with a name returns 422.'],
                             'custom_container_name_prefix' => ['type' => 'string', 'nullable' => true, 'description' => 'Prefix for generated container names (prefix-20260908T141530). Slugified and unique across the instance.'],
                             'preview_url_template' => ['type' => 'string', 'description' => 'Preview URL template.'],
                             'max_restart_count' => ['type' => 'integer', 'minimum' => 0, 'description' => 'Maximum container restart count before stopping.'],
@@ -634,7 +634,7 @@ class ApplicationsController extends Controller
                             'gpu_device_ids' => ['type' => 'string', 'nullable' => true, 'description' => 'Comma-separated GPU device IDs.'],
                             'gpu_options' => ['type' => 'string', 'nullable' => true, 'description' => 'Additional GPU options.'],
                             'is_consistent_container_name_enabled' => ['type' => 'boolean', 'description' => 'Use a consistent container name across deployments.'],
-                            'custom_internal_name' => ['type' => 'string', 'nullable' => true, 'description' => 'Custom internal container name. Requires is_consistent_container_name_enabled to be true.'],
+                            'custom_internal_name' => ['type' => 'string', 'nullable' => true, 'description' => 'Custom internal container name. Turns is_consistent_container_name_enabled on when that field is not sent; sending it as false together with a name returns 422.'],
                             'custom_container_name_prefix' => ['type' => 'string', 'nullable' => true, 'description' => 'Prefix for generated container names (prefix-20260908T141530). Slugified and unique across the instance.'],
                             'preview_url_template' => ['type' => 'string', 'description' => 'Preview URL template.'],
                             'max_restart_count' => ['type' => 'integer', 'minimum' => 0, 'description' => 'Maximum container restart count before stopping.'],
@@ -829,7 +829,7 @@ class ApplicationsController extends Controller
                             'gpu_device_ids' => ['type' => 'string', 'nullable' => true, 'description' => 'Comma-separated GPU device IDs.'],
                             'gpu_options' => ['type' => 'string', 'nullable' => true, 'description' => 'Additional GPU options.'],
                             'is_consistent_container_name_enabled' => ['type' => 'boolean', 'description' => 'Use a consistent container name across deployments.'],
-                            'custom_internal_name' => ['type' => 'string', 'nullable' => true, 'description' => 'Custom internal container name. Requires is_consistent_container_name_enabled to be true.'],
+                            'custom_internal_name' => ['type' => 'string', 'nullable' => true, 'description' => 'Custom internal container name. Turns is_consistent_container_name_enabled on when that field is not sent; sending it as false together with a name returns 422.'],
                             'custom_container_name_prefix' => ['type' => 'string', 'nullable' => true, 'description' => 'Prefix for generated container names (prefix-20260908T141530). Slugified and unique across the instance.'],
                             'preview_url_template' => ['type' => 'string', 'description' => 'Preview URL template.'],
                             'max_restart_count' => ['type' => 'integer', 'minimum' => 0, 'description' => 'Maximum container restart count before stopping.'],
@@ -995,7 +995,7 @@ class ApplicationsController extends Controller
                             'gpu_device_ids' => ['type' => 'string', 'nullable' => true, 'description' => 'Comma-separated GPU device IDs.'],
                             'gpu_options' => ['type' => 'string', 'nullable' => true, 'description' => 'Additional GPU options.'],
                             'is_consistent_container_name_enabled' => ['type' => 'boolean', 'description' => 'Use a consistent container name across deployments.'],
-                            'custom_internal_name' => ['type' => 'string', 'nullable' => true, 'description' => 'Custom internal container name. Requires is_consistent_container_name_enabled to be true.'],
+                            'custom_internal_name' => ['type' => 'string', 'nullable' => true, 'description' => 'Custom internal container name. Turns is_consistent_container_name_enabled on when that field is not sent; sending it as false together with a name returns 422.'],
                             'custom_container_name_prefix' => ['type' => 'string', 'nullable' => true, 'description' => 'Prefix for generated container names (prefix-20260908T141530). Slugified and unique across the instance.'],
                             'preview_url_template' => ['type' => 'string', 'description' => 'Preview URL template.'],
                             'max_restart_count' => ['type' => 'integer', 'minimum' => 0, 'description' => 'Maximum container restart count before stopping.'],
@@ -1157,7 +1157,7 @@ class ApplicationsController extends Controller
                             'gpu_device_ids' => ['type' => 'string', 'nullable' => true, 'description' => 'Comma-separated GPU device IDs.'],
                             'gpu_options' => ['type' => 'string', 'nullable' => true, 'description' => 'Additional GPU options.'],
                             'is_consistent_container_name_enabled' => ['type' => 'boolean', 'description' => 'Use a consistent container name across deployments.'],
-                            'custom_internal_name' => ['type' => 'string', 'nullable' => true, 'description' => 'Custom internal container name. Requires is_consistent_container_name_enabled to be true.'],
+                            'custom_internal_name' => ['type' => 'string', 'nullable' => true, 'description' => 'Custom internal container name. Turns is_consistent_container_name_enabled on when that field is not sent; sending it as false together with a name returns 422.'],
                             'custom_container_name_prefix' => ['type' => 'string', 'nullable' => true, 'description' => 'Prefix for generated container names (prefix-20260908T141530). Slugified and unique across the instance.'],
                             'preview_url_template' => ['type' => 'string', 'description' => 'Preview URL template.'],
                             'max_restart_count' => ['type' => 'integer', 'minimum' => 0, 'description' => 'Maximum container restart count before stopping.'],
@@ -3151,7 +3151,7 @@ class ApplicationsController extends Controller
                             'gpu_device_ids' => ['type' => 'string', 'nullable' => true, 'description' => 'Comma-separated GPU device IDs.'],
                             'gpu_options' => ['type' => 'string', 'nullable' => true, 'description' => 'Additional GPU options.'],
                             'is_consistent_container_name_enabled' => ['type' => 'boolean', 'description' => 'Use a consistent container name across deployments.'],
-                            'custom_internal_name' => ['type' => 'string', 'nullable' => true, 'description' => 'Custom internal container name. Requires is_consistent_container_name_enabled to be true.'],
+                            'custom_internal_name' => ['type' => 'string', 'nullable' => true, 'description' => 'Custom internal container name. Turns is_consistent_container_name_enabled on when that field is not sent; sending it as false together with a name returns 422.'],
                             'custom_container_name_prefix' => ['type' => 'string', 'nullable' => true, 'description' => 'Prefix for generated container names (prefix-20260908T141530). Slugified and unique across the instance.'],
                             'preview_url_template' => ['type' => 'string', 'description' => 'Preview URL template.'],
                             'max_restart_count' => ['type' => 'integer', 'minimum' => 0, 'description' => 'Maximum container restart count before stopping.'],
@@ -3335,7 +3335,7 @@ class ApplicationsController extends Controller
         if ($prefixValidation = $this->containerNamePrefixValidationResponse($applicationSettings, $application->destination->server, $application)) {
             return $prefixValidation;
         }
-        if ($internalNameValidation = $this->customInternalNameValidationResponse($applicationSettings, $application)) {
+        if ($internalNameValidation = $this->customInternalNameValidationResponse($applicationSettings)) {
             return $internalNameValidation;
         }
         $requestedBuildPack = $request->input('build_pack', $application->build_pack);
diff --git a/openapi.json b/openapi.json
index f3a237b856..9c89dcf413 100644
--- a/openapi.json
+++ b/openapi.json
@@ -950,7 +950,7 @@
                                     "custom_internal_name": {
                                         "type": "string",
                                         "nullable": true,
-                                        "description": "Custom internal container name. Requires is_consistent_container_name_enabled to be true."
+                                        "description": "Custom internal container name. Turns is_consistent_container_name_enabled on when that field is not sent; sending it as false together with a name returns 422."
                                     },
                                     "custom_container_name_prefix": {
                                         "type": "string",
@@ -1541,7 +1541,7 @@
                                     "custom_internal_name": {
                                         "type": "string",
                                         "nullable": true,
-                                        "description": "Custom internal container name. Requires is_consistent_container_name_enabled to be true."
+                                        "description": "Custom internal container name. Turns is_consistent_container_name_enabled on when that field is not sent; sending it as false together with a name returns 422."
                                     },
                                     "custom_container_name_prefix": {
                                         "type": "string",
@@ -2132,7 +2132,7 @@
                                     "custom_internal_name": {
                                         "type": "string",
                                         "nullable": true,
-                                        "description": "Custom internal container name. Requires is_consistent_container_name_enabled to be true."
+                                        "description": "Custom internal container name. Turns is_consistent_container_name_enabled on when that field is not sent; sending it as false together with a name returns 422."
                                     },
                                     "custom_container_name_prefix": {
                                         "type": "string",
@@ -2618,7 +2618,7 @@
                                     "custom_internal_name": {
                                         "type": "string",
                                         "nullable": true,
-                                        "description": "Custom internal container name. Requires is_consistent_container_name_enabled to be true."
+                                        "description": "Custom internal container name. Turns is_consistent_container_name_enabled on when that field is not sent; sending it as false together with a name returns 422."
                                     },
                                     "custom_container_name_prefix": {
                                         "type": "string",
@@ -3084,7 +3084,7 @@
                                     "custom_internal_name": {
                                         "type": "string",
                                         "nullable": true,
-                                        "description": "Custom internal container name. Requires is_consistent_container_name_enabled to be true."
+                                        "description": "Custom internal container name. Turns is_consistent_container_name_enabled on when that field is not sent; sending it as false together with a name returns 422."
                                     },
                                     "custom_container_name_prefix": {
                                         "type": "string",
@@ -3795,7 +3795,7 @@
                                     "custom_internal_name": {
                                         "type": "string",
                                         "nullable": true,
-                                        "description": "Custom internal container name. Requires is_consistent_container_name_enabled to be true."
+                                        "description": "Custom internal container name. Turns is_consistent_container_name_enabled on when that field is not sent; sending it as false together with a name returns 422."
                                     },
                                     "custom_container_name_prefix": {
                                         "type": "string",
diff --git a/openapi.yaml b/openapi.yaml
index 405551392b..802aee71a7 100644
--- a/openapi.yaml
+++ b/openapi.yaml
@@ -623,7 +623,7 @@ paths:
                 custom_internal_name:
                   type: string
                   nullable: true
-                  description: 'Custom internal container name. Requires is_consistent_container_name_enabled to be true.'
+                  description: 'Custom internal container name. Turns is_consistent_container_name_enabled on when that field is not sent; sending it as false together with a name returns 422.'
                 custom_container_name_prefix:
                   type: string
                   nullable: true
@@ -1009,7 +1009,7 @@ paths:
                 custom_internal_name:
                   type: string
                   nullable: true
-                  description: 'Custom internal container name. Requires is_consistent_container_name_enabled to be true.'
+                  description: 'Custom internal container name. Turns is_consistent_container_name_enabled on when that field is not sent; sending it as false together with a name returns 422.'
                 custom_container_name_prefix:
                   type: string
                   nullable: true
@@ -1395,7 +1395,7 @@ paths:
                 custom_internal_name:
                   type: string
                   nullable: true
-                  description: 'Custom internal container name. Requires is_consistent_container_name_enabled to be true.'
+                  description: 'Custom internal container name. Turns is_consistent_container_name_enabled on when that field is not sent; sending it as false together with a name returns 422.'
                 custom_container_name_prefix:
                   type: string
                   nullable: true
@@ -1722,7 +1722,7 @@ paths:
                 custom_internal_name:
                   type: string
                   nullable: true
-                  description: 'Custom internal container name. Requires is_consistent_container_name_enabled to be true.'
+                  description: 'Custom internal container name. Turns is_consistent_container_name_enabled on when that field is not sent; sending it as false together with a name returns 422.'
                 custom_container_name_prefix:
                   type: string
                   nullable: true
@@ -2035,7 +2035,7 @@ paths:
                 custom_internal_name:
                   type: string
                   nullable: true
-                  description: 'Custom internal container name. Requires is_consistent_container_name_enabled to be true.'
+                  description: 'Custom internal container name. Turns is_consistent_container_name_enabled on when that field is not sent; sending it as false together with a name returns 422.'
                 custom_container_name_prefix:
                   type: string
                   nullable: true
@@ -2502,7 +2502,7 @@ paths:
                 custom_internal_name:
                   type: string
                   nullable: true
-                  description: 'Custom internal container name. Requires is_consistent_container_name_enabled to be true.'
+                  description: 'Custom internal container name. Turns is_consistent_container_name_enabled on when that field is not sent; sending it as false together with a name returns 422.'
                 custom_container_name_prefix:
                   type: string
                   nullable: true
diff --git a/tests/Feature/Api/ApplicationCustomInternalNameConsistentNamingApiTest.php b/tests/Feature/Api/ApplicationCustomInternalNameConsistentNamingApiTest.php
index f745425781..e50274f3d4 100644
--- a/tests/Feature/Api/ApplicationCustomInternalNameConsistentNamingApiTest.php
+++ b/tests/Feature/Api/ApplicationCustomInternalNameConsistentNamingApiTest.php
@@ -51,13 +51,28 @@ function customInternalNameCreatePayload(array $overrides): array
 
 const CUSTOM_INTERNAL_NAME_NEEDS_CONSISTENT_NAMING = 'Set is_consistent_container_name_enabled to true to use custom_internal_name. Coolify ignores the custom internal name while consistent container naming is turned off.';
 
-test('updating only custom_internal_name is rejected while consistent container naming is off', function () {
+test('updating only custom_internal_name turns consistent container naming on', function () {
     $this->withToken($this->bearerToken)
         ->patchJson("/api/v1/applications/{$this->application->uuid}", ['custom_internal_name' => 'my-app'])
+        ->assertOk();
+
+    $settings = $this->application->fresh()->settings;
+    expect($settings->custom_internal_name)->toBe('my-app')
+        ->and($settings->is_consistent_container_name_enabled)->toBeTrue();
+});
+
+test('updating custom_internal_name with consistent container naming explicitly off is rejected', function () {
+    $this->withToken($this->bearerToken)
+        ->patchJson("/api/v1/applications/{$this->application->uuid}", [
+            'custom_internal_name' => 'my-app',
+            'is_consistent_container_name_enabled' => false,
+        ])
         ->assertUnprocessable()
         ->assertJsonPath('errors.custom_internal_name.0', CUSTOM_INTERNAL_NAME_NEEDS_CONSISTENT_NAMING);
 
-    expect($this->application->fresh()->settings->custom_internal_name)->toBeNull();
+    $settings = $this->application->fresh()->settings;
+    expect($settings->custom_internal_name)->toBeNull()
+        ->and($settings->is_consistent_container_name_enabled)->toBeFalse();
 });
 
 test('updating custom_internal_name while turning consistent container naming off is rejected', function () {
@@ -99,13 +114,30 @@ test('clearing custom_internal_name does not need consistent container naming',
     $this->withToken($this->bearerToken)
         ->patchJson("/api/v1/applications/{$this->application->uuid}", ['custom_internal_name' => $value])
         ->assertOk();
+
+    expect($this->application->fresh()->settings->is_consistent_container_name_enabled)->toBeFalse();
 })->with(['null' => [null], 'empty string' => ['']]);
 
-test('creating an application with custom_internal_name requires consistent container naming', function () {
+test('creating an application with only custom_internal_name turns consistent container naming on', function () {
+    Queue::fake();
+
+    $response = $this->withToken($this->bearerToken)
+        ->postJson('/api/v1/applications/public', customInternalNameCreatePayload(['custom_internal_name' => 'my-app']))
+        ->assertCreated();
+
+    $settings = Application::query()->where('uuid', $response->json('uuid'))->sole()->settings;
+    expect($settings->custom_internal_name)->toBe('my-app')
+        ->and($settings->is_consistent_container_name_enabled)->toBeTrue();
+});
+
+test('creating an application with custom_internal_name and consistent container naming explicitly off is rejected', function () {
     Queue::fake();
 
     $this->withToken($this->bearerToken)
-        ->postJson('/api/v1/applications/public', customInternalNameCreatePayload(['custom_internal_name' => 'my-app']))
+        ->postJson('/api/v1/applications/public', customInternalNameCreatePayload([
+            'custom_internal_name' => 'my-app',
+            'is_consistent_container_name_enabled' => false,
+        ]))
         ->assertUnprocessable()
         ->assertJsonPath('errors.custom_internal_name.0', CUSTOM_INTERNAL_NAME_NEEDS_CONSISTENT_NAMING);