diff --git a/app/Keycloak/Converters/IntegrationUrlConverter.php b/app/Keycloak/Converters/IntegrationUrlConverter.php
index 0ffd47831..5f6dbf23a 100644
--- a/app/Keycloak/Converters/IntegrationUrlConverter.php
+++ b/app/Keycloak/Converters/IntegrationUrlConverter.php
@@ -54,6 +54,6 @@ public static function buildLogoutUrls(Integration $integration, Environment $en
         }
 
         $logoutUrls = $integration->urlsForTypeAndEnvironment(IntegrationUrlType::Logout, $environment);
-        return implode('#', array_map(static fn ($url) => $url->url, $logoutUrls));
+        return implode('##', array_map(static fn ($url) => $url->url, $logoutUrls));
     }
 }
diff --git a/tests/Keycloak/Converters/IntegrationToKeycloakClientConverterTest.php b/tests/Keycloak/Converters/IntegrationToKeycloakClientConverterTest.php
index b3948b906..67e2a3dd2 100644
--- a/tests/Keycloak/Converters/IntegrationToKeycloakClientConverterTest.php
+++ b/tests/Keycloak/Converters/IntegrationToKeycloakClientConverterTest.php
@@ -83,7 +83,7 @@ public function test_combining_keycloak_convert_with_configured_uris(): void
         $this->assertEquals([
             'origin' => 'publiq-platform',
             'use.refresh.tokens' => true,
-            'post.logout.redirect.uris' => 'https://example.com/logout1#https://example.com/logout2',
+            'post.logout.redirect.uris' => 'https://example.com/logout1##https://example.com/logout2',
         ], $convertedData['attributes']);
         $this->assertEquals('https://example.com/login1', $convertedData['baseUrl']);
         $this->assertEquals(['https://example.com/callback1', 'https://example.com/callback2'], $convertedData['redirectUris']);
diff --git a/tests/Keycloak/Converters/IntegrationUrlConverterTest.php b/tests/Keycloak/Converters/IntegrationUrlConverterTest.php
index ba92aabb5..d4843b632 100644
--- a/tests/Keycloak/Converters/IntegrationUrlConverterTest.php
+++ b/tests/Keycloak/Converters/IntegrationUrlConverterTest.php
@@ -99,7 +99,7 @@ public function test_convert_for_first_party_logout_urls(): void
             new IntegrationUrl(Uuid::uuid4(), $integration->id, Environment::Production, IntegrationUrlType::Logout, 'https://wrong.com/'),
         );
         $this->assertSame(
-            'https://example.com/logout1#https://example.com/logout2',
+            'https://example.com/logout1##https://example.com/logout2',
             IntegrationUrlConverter::buildLogoutUrls($integration, $this->client->environment)
         );
     }