diff --git a/commerce_discount.module b/commerce_discount.module
index 3923be5..f6083f9 100644
--- a/commerce_discount.module
+++ b/commerce_discount.module
@@ -382,110 +382,119 @@ function commerce_discount_commerce_discount_update($entity) {
 /**
  * Actually rebuild the defaults of a given entity.
  *
+ * @see entity_defaults_rebuild().
+ *
  * @param CommerceDiscount $discount
- *    Fully loaded Commerce Discount entity to rebuild rules_config for.
+ *   Fully loaded Commerce Discount entity to rebuild rules_config for.
  */
 function _commerce_discount_rebuild_rules_config(CommerceDiscount $discount) {
-  if (lock_acquire('entity_rebuild_rules_config')) {
-    $existing_rules_config = FALSE;
-    $rules_config_name = 'commerce_discount_rule_' . $discount->name;
+  // Return early if we can't aquire a lock on the rules config.
+  if (!lock_acquire('entity_rebuild_rules_config')) {
+    return;
+  }
 
-    $info = entity_get_info('rules_config');
-    $hook = isset($info['export']['default hook']) ? $info['export']['default hook'] : 'default_rules_config';
-    $keys = $info['entity keys'] + array('module' => 'module', 'status' => 'status', 'name' => $info['entity keys']['id']);
+  $existing_rules_config = FALSE;
+  $rules_config_name = 'commerce_discount_rule_' . $discount->name;
 
-    // Check for the existence of the module and status columns.
-    if (!in_array($keys['status'], $info['schema_fields_sql']['base table']) || !in_array($keys['module'], $info['schema_fields_sql']['base table'])) {
-      trigger_error("Missing database columns for the exportable entity 'rules_config' as defined by entity_exportable_schema_fields(). Update the according module and run update.php!", E_USER_WARNING);
-      return;
-    }
+  $info = entity_get_info('rules_config');
+  $hook = isset($info['export']['default hook']) ? $info['export']['default hook'] : 'default_rules_config';
+  $keys = $info['entity keys'] + array(
+    'module' => 'module',
+    'status' => 'status',
+    'name' => $info['entity keys']['id'],
+  );
 
-    // Invoke the hook and collect default entities.
-    $entities = array();
-    foreach (module_implements($hook) as $module) {
-      /** @var RulesReactionRule $entity */
-      foreach ((array) module_invoke($module, $hook) as $name => $entity) {
-        if ($name == $rules_config_name) {
-          $entity->{$keys['name']} = $name;
-          $entity->{$keys['module']} = $module;
-          $entities[$name] = $entity;
-          $existing_rules_config = TRUE;
-        }
-      }
-    }
-    drupal_alter($hook, $entities);
-
-    // Check for defaults that disappeared or overridden?
-    if (!$existing_rules_config) {
-      $existing_defaults = entity_load_multiple_by_name('rules_config', FALSE, array($keys['status'] => array(ENTITY_OVERRIDDEN, ENTITY_IN_CODE, ENTITY_FIXED)));
-
-      foreach ($existing_defaults as $name => $entity) {
-        if (empty($entities[$name]) && $name == $rules_config_name) {
-          $entity->is_rebuild = TRUE;
-          if (entity_has_status('rules_config', $entity, ENTITY_OVERRIDDEN)) {
-            $entity->{$keys['status']} = ENTITY_CUSTOM;
-            entity_save('rules_config', $entity);
-          }
-          else {
-            entity_delete('rules_config', $name);
-          }
-          unset($entity->is_rebuild);
-        }
+  // Check for the existence of the module and status columns.
+  if (!in_array($keys['status'], $info['schema_fields_sql']['base table']) || !in_array($keys['module'], $info['schema_fields_sql']['base table'])) {
+    trigger_error("Missing database columns for the exportable entity 'rules_config' as defined by entity_exportable_schema_fields(). Update the according module and run update.php!", E_USER_WARNING);
+    return;
+  }
+
+  // Invoke the hook and collect default entities.
+  $entities = array();
+  foreach (module_implements($hook) as $module) {
+    /** @var RulesReactionRule $entity */
+    foreach ((array) module_invoke($module, $hook) as $name => $entity) {
+      if ($name == $rules_config_name) {
+        $entity->{$keys['name']} = $name;
+        $entity->{$keys['module']} = $module;
+        $entities[$name] = $entity;
+        $existing_rules_config = TRUE;
       }
     }
+  }
+  drupal_alter($hook, $entities);
+
+  // Check for defaults that disappeared or overridden?
+  if (!$existing_rules_config) {
+    $existing_defaults = entity_load_multiple_by_name('rules_config', FALSE, array($keys['status'] => array(ENTITY_OVERRIDDEN, ENTITY_IN_CODE, ENTITY_FIXED)));
 
-    // Load all existing entities.
-    $existing_entities = entity_load_multiple_by_name('rules_config', array_keys($entities));
-
-    foreach ($existing_entities as $name => $entity) {
-      if (entity_has_status('rules_config', $entity, ENTITY_CUSTOM)) {
-        // If the entity already exists but is not yet marked as overridden, we
-        // have to update the status.
-        if (!entity_has_status('rules_config', $entity, ENTITY_OVERRIDDEN)) {
-          $entity->{$keys['status']} |= ENTITY_OVERRIDDEN;
-          $entity->{$keys['module']} = $entities[$name]->{$keys['module']};
-          $entity->is_rebuild = TRUE;
+    foreach ($existing_defaults as $name => $entity) {
+      if (empty($entities[$name]) && $name == $rules_config_name) {
+        $entity->is_rebuild = TRUE;
+        if (entity_has_status('rules_config', $entity, ENTITY_OVERRIDDEN)) {
+          $entity->{$keys['status']} = ENTITY_CUSTOM;
           entity_save('rules_config', $entity);
-          unset($entity->is_rebuild);
         }
-
-        // The entity is overridden, so we do not need to save the default.
-        unset($entities[$name]);
+        else {
+          entity_delete('rules_config', $name);
+        }
+        unset($entity->is_rebuild);
       }
     }
+  }
 
-    // Save defaults.
-    $originals = array();
-    foreach ($entities as $name => $entity) {
-      if (!empty($existing_entities[$name])) {
-        // Make sure we are updating the existing default.
-        $entity->{$keys['id']} = $existing_entities[$name]->{$keys['id']};
-        unset($entity->is_new);
+  // Load all existing entities.
+  $existing_entities = entity_load_multiple_by_name('rules_config', array_keys($entities));
+
+  foreach ($existing_entities as $name => $entity) {
+    if (entity_has_status('rules_config', $entity, ENTITY_CUSTOM)) {
+      // If the entity already exists but is not yet marked as overridden, we
+      // have to update the status.
+      if (!entity_has_status('rules_config', $entity, ENTITY_OVERRIDDEN)) {
+        $entity->{$keys['status']} |= ENTITY_OVERRIDDEN;
+        $entity->{$keys['module']} = $entities[$name]->{$keys['module']};
+        $entity->is_rebuild = TRUE;
+        entity_save('rules_config', $entity);
+        unset($entity->is_rebuild);
       }
-      // Pre-populate $entity->original as we already have it. So we avoid
-      // loading it again.
-      $entity->original = !empty($existing_entities[$name]) ? $existing_entities[$name] : FALSE;
-      // Keep original entities for hook_{entity_type}_defaults_rebuild()
-      // implementations.
-      $originals[$name] = $entity->original;
-
-      if (!isset($entity->{$keys['status']})) {
-        $entity->{$keys['status']} = ENTITY_IN_CODE;
-      }
-      else {
-        $entity->{$keys['status']} |= ENTITY_IN_CODE;
-      }
-      $entity->is_rebuild = TRUE;
-      entity_save('rules_config', $entity);
-      unset($entity->is_rebuild);
-    }
 
-    // Invoke an entity type-specific hook so modules may apply changes, e.g.
-    // efficiently rebuild caches.
-    module_invoke_all('rules_config' . '_defaults_rebuild', $entities, $originals);
+      // The entity is overridden, so we do not need to save the default.
+      unset($entities[$name]);
+    }
+  }
 
-    lock_release('entity_rebuild_rules_config');
+  // Save defaults.
+  $originals = array();
+  foreach ($entities as $name => $entity) {
+    if (!empty($existing_entities[$name])) {
+      // Make sure we are updating the existing default.
+      $entity->{$keys['id']} = $existing_entities[$name]->{$keys['id']};
+      unset($entity->is_new);
+    }
+    // Pre-populate $entity->original as we already have it. So we avoid
+    // loading it again.
+    $entity->original = !empty($existing_entities[$name]) ? $existing_entities[$name] : FALSE;
+    // Keep original entities for hook_{entity_type}_defaults_rebuild()
+    // implementations.
+    $originals[$name] = $entity->original;
+
+    if (!isset($entity->{$keys['status']})) {
+      $entity->{$keys['status']} = ENTITY_IN_CODE;
+    }
+    else {
+      $entity->{$keys['status']} |= ENTITY_IN_CODE;
+    }
+    $entity->is_rebuild = TRUE;
+    entity_save('rules_config', $entity);
+    unset($entity->is_rebuild);
   }
+
+  // Invoke an entity type-specific hook so modules may apply changes, e.g.
+  // efficiently rebuild caches.
+  module_invoke_all('rules_config_defaults_rebuild', $entities, $originals);
+
+  lock_release('entity_rebuild_rules_config');
 }
 
 /**