diff --git a/CRM/Core/Resources/Common.php b/CRM/Core/Resources/Common.php
index 5f11d0314fb4..92fff3159af9 100644
--- a/CRM/Core/Resources/Common.php
+++ b/CRM/Core/Resources/Common.php
@@ -97,7 +97,7 @@ public static function createStyleBundle($name) {
     $config = CRM_Core_Config::singleton();
     if (!empty($config->customCSSURL)) {
       $customCSSURL = Civi::resources()->addCacheCode($config->customCSSURL);
-      $bundle->addStyleUrl($customCSSURL, 99);
+      $bundle->addStyleUrl($customCSSURL, ['weight' => 99, 'name' => 'civicrm:css/custom.css']);
     }
     if (!Civi::settings()->get('disable_core_css')) {
       $bundle->addStyleFile('civicrm', 'css/civicrm.css', -99);
diff --git a/tests/phpunit/CRM/Core/Resources/BundleTest.php b/tests/phpunit/CRM/Core/Resources/BundleTest.php
index 08490b979471..b456b8665718 100644
--- a/tests/phpunit/CRM/Core/Resources/BundleTest.php
+++ b/tests/phpunit/CRM/Core/Resources/BundleTest.php
@@ -72,4 +72,16 @@ public function testFillDefaults() {
     $this->assertEquals('page-header', $bundle->get('cheese')['region']);
   }
 
+  /**
+   * Test creation of coreStyles bundle
+   */
+  public function testCoreStylesBundle() {
+    $config = CRM_Core_Config::singleton();
+    $config->customCSSURL = "http://example.com/css/custom.css";
+    $bundle = CRM_Core_Resources_Common::createStyleBundle('coreStyles');
+    $this->assertEquals('civicrm:css/civicrm.css', $bundle->get('civicrm:css/civicrm.css')['name']);
+    $this->assertEquals('civicrm:css/crm-i.css', $bundle->get('civicrm:css/crm-i.css')['name']);
+    $this->assertEquals('civicrm:css/custom.css', $bundle->get('civicrm:css/custom.css')['name']);
+  }
+
 }