diff --git a/CRM/Contract/CustomData.php b/CRM/Contract/CustomData.php
index fbf9c00..e37d04e 100644
--- a/CRM/Contract/CustomData.php
+++ b/CRM/Contract/CustomData.php
@@ -47,161 +47,6 @@ protected function log($level, $message) {
     }
   }
 
-  /**
-   * will take a JSON source file and synchronise the
-   * generic entity data with those specs
-   */
-  public function syncEntities($source_file) {
-    $data = json_decode(file_get_contents($source_file), TRUE);
-    if (empty($data)) {
-      throw new Exception("syncEntities: Invalid specs");
-    }
-
-    foreach ($data['_entities'] as $entity_data) {
-      $this->translateStrings($entity_data);
-      $entity = $this->identifyEntity($data['entity'], $entity_data);
-
-      if (empty($entity)) {
-        // create OptionValue
-        $entity = $this->createEntity($data['entity'], $entity_data);
-      } elseif ($entity == 'FAILED') {
-        // Couldn't identify:
-        $this->log(CUSTOM_DATA_HELPER_LOG_ERROR, "Couldn't create/update {$data['entity']}: " . json_encode($entity_data));
-      } else {
-        // update OptionValue
-        $this->updateEntity($data['entity'], $entity_data, $entity);
-      }
-    }
-  }
-
-  /**
-   * will take a JSON source file and synchronise the
-   * OptionGroup/OptionValue data in the system with
-   * those specs
-   */
-  public function syncOptionGroup($source_file) {
-    $data = json_decode(file_get_contents($source_file), TRUE);
-    if (empty($data)) {
-      throw new Exception("syncOptionGroup: Invalid specs");
-    }
-
-    // first: find or create option group
-    $this->translateStrings($data);
-    $optionGroup = $this->identifyEntity('OptionGroup', $data);
-    if (empty($optionGroup)) {
-      // create OptionGroup
-      $optionGroup = $this->createEntity('OptionGroup', $data);
-    } elseif ($optionGroup == 'FAILED') {
-      // Couldn't identify:
-      $this->log(CUSTOM_DATA_HELPER_LOG_ERROR, "Couldn't create/update OptionGroup: " . json_encode($data));
-      return;
-    } else {
-      // update OptionGroup
-      $this->updateEntity('OptionGroup', $data, $optionGroup, array('is_active'));
-    }
-
-    // now run the update for the OptionValues
-    foreach ($data['_values'] as $optionValueSpec) {
-      $this->translateStrings($optionValueSpec);
-      $optionValueSpec['option_group_id'] = $optionGroup['id'];
-      $optionValueSpec['_lookup'][] = 'option_group_id';
-      $optionValue = $this->identifyEntity('OptionValue', $optionValueSpec);
-
-      if (empty($optionValue)) {
-        // create OptionValue
-        $optionValue = $this->createEntity('OptionValue', $optionValueSpec);
-      } elseif ($optionValue == 'FAILED') {
-        // Couldn't identify:
-        $this->log(CUSTOM_DATA_HELPER_LOG_ERROR, "Couldn't create/update OptionValue: " . json_encode($optionValueSpec));
-      } else {
-        // update OptionValue
-        $this->updateEntity('OptionValue', $optionValueSpec, $optionValue, array('is_active'));
-      }
-    }
-  }
-
-
-  /**
-   * will take a JSON source file and synchronise the
-   * CustomGroup/CustomField data in the system with
-   * those specs
-   */
-  public function syncCustomGroup($source_file) {
-    $force_update = FALSE;
-    $data = json_decode(file_get_contents($source_file), TRUE);
-    if (empty($data)) {
-      throw new Exception("CRM_Utils_CustomData::syncCustomGroup: Invalid custom specs");
-    }
-
-    // if extends_entity_column_value, make sure it's sensible data
-    if (isset($data['extends_entity_column_value'])) {
-      $force_update = TRUE; // this doesn't get returned by the API, so differences couldn't be detected
-      if ($data['extends'] == 'Activity') {
-        $extends_list = array();
-        foreach ($data['extends_entity_column_value'] as $activity_type) {
-          if (!is_numeric($activity_type)) {
-            $activity_type = CRM_Core_PseudoConstant::getKey(
-              'CRM_Activity_BAO_Activity',
-              'activity_type_id',
-              $activity_type
-            );
-          }
-          if ($activity_type) {
-            $extends_list[] = $activity_type;
-          }
-        }
-        $data['extends_entity_column_value'] = $extends_list;
-      }
-
-      if (is_array($data['extends_entity_column_value'])) {
-        $data['extends_entity_column_value'] = CRM_Utils_Array::implodePadded($data['extends_entity_column_value']);
-      }
-    }
-
-
-    // first: find or create custom group
-    $this->translateStrings($data);
-    $customGroup = $this->identifyEntity('CustomGroup', $data);
-    if (empty($customGroup)) {
-      // create CustomGroup
-      $customGroup = $this->createEntity('CustomGroup', $data);
-    } elseif ($customGroup == 'FAILED') {
-      // Couldn't identify:
-      $this->log(CUSTOM_DATA_HELPER_LOG_ERROR, "Couldn't create/update CustomGroup: " . json_encode($data));
-      return;
-    } else {
-      // update CustomGroup
-      $this->updateEntity('CustomGroup', $data, $customGroup, array('extends', 'style', 'is_active', 'title', 'extends_entity_column_value'), $force_update);
-    }
-
-    // now run the update for the CustomFields
-    foreach ($data['_fields'] as $customFieldSpec) {
-      $this->translateStrings($customFieldSpec);
-      $customFieldSpec['custom_group_id'] = $customGroup['id'];
-      $customFieldSpec['_lookup'][] = 'custom_group_id';
-      if (!empty($customFieldSpec['option_group_id']) && !is_numeric($customFieldSpec['option_group_id'])) {
-        // look up custom group id
-        $optionGroup = $this->getEntityID('OptionGroup', array('name' => $customFieldSpec['option_group_id']));
-        if ($optionGroup == 'FAILED' || $optionGroup==NULL) {
-          $this->log(CUSTOM_DATA_HELPER_LOG_ERROR, "Couldn't create/update CustomField, bad option_group: {$customFieldSpec['option_group_id']}");
-          return;
-        }
-        $customFieldSpec['option_group_id'] = $optionGroup['id'];
-      }
-      $customField = $this->identifyEntity('CustomField', $customFieldSpec);
-      if (empty($customField)) {
-        // create CustomField
-        $customField = $this->createEntity('CustomField', $customFieldSpec);
-      } elseif ($customField == 'FAILED') {
-        // Couldn't identify:
-        $this->log(CUSTOM_DATA_HELPER_LOG_ERROR, "Couldn't create/update CustomField: " . json_encode($customFieldSpec));
-      } else {
-        // update CustomField
-        $this->updateEntity('CustomField', $customFieldSpec, $customField, array('in_selector', 'is_view', 'is_searchable', 'html_type', 'data_type', 'custom_group_id'));
-      }
-    }
-  }
-
   /**
    * return the ID of the given entity (if exists)
    */
diff --git a/CRM/Contract/Upgrader.php b/CRM/Contract/Upgrader.php
index 9073219..249c7a2 100644
--- a/CRM/Contract/Upgrader.php
+++ b/CRM/Contract/Upgrader.php
@@ -22,9 +22,6 @@ public function install() {
   }
 
   public function enable() {
-    require_once 'CRM/Contract/CustomData.php';
-    $customData = new CRM_Contract_CustomData('de.systopia.contract');
-
     // create sub-type 'Dialoger'
     $dialoger_exists = civicrm_api3('ContactType', 'getcount', ['name' => 'Dialoger']);
     if (!$dialoger_exists) {
@@ -41,18 +38,6 @@ public function postInstall() {
   public function uninstall() {
   }
 
-  /**
-   * Add custom field "defer_payment_start"
-   *
-   * @return TRUE on success
-   * @throws Exception
-   */
-  public function upgrade_1360() {
-    $this->ctx->log->info('Applying update 1360');
-    $customData = new CRM_Contract_CustomData('de.systopia.contract');
-    return TRUE;
-  }
-
   public function upgrade_1370() {
     $this->ctx->log->info('Applying update 1370');
     $this->executeSqlFile('sql/contract.sql');
@@ -66,12 +51,6 @@ public function upgrade_1390() {
     return TRUE;
   }
 
-  public function upgrade_1402() {
-    $this->ctx->log->info('Applying updates for 14xx');
-    $customData = new CRM_Contract_CustomData('de.systopia.contract');
-    return TRUE;
-  }
-
   /**
    * Convert scheduled legacy update activities by adding ch_payment_changes
    *
@@ -118,9 +97,4 @@ public function upgrade_1500() {
     return TRUE;
   }
 
-  public function upgrade_1510() {
-    $this->ctx->log->info('Applying update 1510');
-    $customData = new CRM_Contract_CustomData('de.systopia.contract');
-    return TRUE;
-  }
 }