diff --git a/src/Entity/Index.php b/src/Entity/Index.php
index 70b54b8..54826fc 100644
--- a/src/Entity/Index.php
+++ b/src/Entity/Index.php
@@ -756,7 +756,7 @@ class Index extends ConfigEntityBase implements IndexInterface {
               /** @var \Drupal\search_api\Item\AdditionalFieldInterface $additional_field */
               $additional_field = $this->fields[0]['additional fields'][$property_path];
               $additional_field->setEnabled(TRUE);
-              $additional_field->setLocked(TRUE);
+              $additional_field->setLocked();
             }
           }
         }
@@ -809,11 +809,12 @@ class Index extends ConfigEntityBase implements IndexInterface {
       // To make it possible to lock fields that are, technically, nested, use
       // the original $property for this check.
       if ($original_property instanceof PropertyInterface) {
-        $field->setLocked($original_property->isLocked());
+        $field->setIndexedLocked($original_property->isIndexedLocked());
+        $field->setTypeLocked($original_property->isTypeLocked());
         $field->setHidden($original_property->isHidden());
       }
       $this->fields[0]['fields'][$key] = $field;
-      if (isset($field_options[$key]) || $field->isLocked()) {
+      if (isset($field_options[$key]) || $field->isIndexedLocked()) {
         $field->setIndexed(TRUE);
         if (isset($field_options[$key])) {
           $field->setType($field_options[$key]['type']);
@@ -1226,7 +1227,7 @@ class Index extends ConfigEntityBase implements IndexInterface {
     $datasource_ids = array_merge(array(NULL), $this->getDatasourceIds());
     foreach ($datasource_ids as $datasource_id) {
       foreach ($this->getPropertyDefinitions($datasource_id) as $key => $property) {
-        if ($property instanceof PropertyInterface && $property->isLocked()) {
+        if ($property instanceof PropertyInterface && $property->isIndexedLocked()) {
           $settings = $property->getFieldSettings();
           if (empty($settings['type'])) {
             $mapping = Utility::getFieldTypeMapping();
diff --git a/src/Form/IndexFieldsForm.php b/src/Form/IndexFieldsForm.php
index e53ecd6..304dfdd 100644
--- a/src/Form/IndexFieldsForm.php
+++ b/src/Form/IndexFieldsForm.php
@@ -185,6 +185,7 @@ class IndexFieldsForm extends EntityForm {
       $build['fields'][$key]['indexed'] = array(
         '#type' => 'checkbox',
         '#default_value' => $field->isIndexed(),
+        '#disabled' => $field->isIndexedLocked(),
       );
       $css_key = '#edit-fields-' . Html::getId($key);
       $build['fields'][$key]['type'] = array(
@@ -196,6 +197,7 @@ class IndexFieldsForm extends EntityForm {
             $css_key . '-indexed' => array('checked' => TRUE),
           ),
         ),
+        '#disabled' => $field->isTypeLocked(),
       );
       $build['fields'][$key]['boost'] = array(
         '#type' => 'select',
@@ -210,7 +212,6 @@ class IndexFieldsForm extends EntityForm {
       foreach ($fulltext_types as $type) {
         $build['fields'][$key]['boost']['#states']['visible'][$css_key . '-type'][] = array('value' => $type);
       }
-      $build['fields'][$key]['#disabled'] = $field->isLocked();
       $build['fields'][$key]['#access'] = !$field->isHidden();
     }
 
diff --git a/src/Item/AdditionalField.php b/src/Item/AdditionalField.php
index 1e1e84a..e3e8a23 100644
--- a/src/Item/AdditionalField.php
+++ b/src/Item/AdditionalField.php
@@ -22,6 +22,13 @@ class AdditionalField implements AdditionalFieldInterface {
   protected $enabled;
 
   /**
+   * Whether this additional field is locked.
+   *
+   * @var bool
+   */
+  protected $locked;
+
+  /**
    * {@inheritdoc}
    */
   public function isEnabled() {
@@ -54,13 +61,16 @@ class AdditionalField implements AdditionalFieldInterface {
   }
 
   /**
-   * Determines whether this additional field's state should be locked.
-   *
-   * @return bool
-   *   TRUE if a child of this additional field is enabled or the field was
-   *   nevertheless marked as locked, FALSE otherwise.
-   *
-   * @see \Drupal\search_api\Item\GenericFieldInterface::isLocked()
+   * {@inheritdoc}
+   */
+  public function setLocked($locked = TRUE) {
+    $this->locked = $locked;
+
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
    */
   public function isLocked() {
     if (!isset($this->locked)) {
@@ -74,7 +84,6 @@ class AdditionalField implements AdditionalFieldInterface {
           break;
         }
       }
-
     }
     return $this->locked;
   }
diff --git a/src/Item/AdditionalFieldInterface.php b/src/Item/AdditionalFieldInterface.php
index 29041eb..a832d8a 100644
--- a/src/Item/AdditionalFieldInterface.php
+++ b/src/Item/AdditionalFieldInterface.php
@@ -33,4 +33,23 @@ interface AdditionalFieldInterface extends GenericFieldInterface {
    */
   public function setEnabled($enabled, $notify = FALSE);
 
+  /**
+   * Sets whether this additional field is locked or not.
+   *
+   * @param bool $locked
+   *   The new locked state of this additional field.
+   *
+   * @return $this
+   */
+  public function setLocked($locked = TRUE);
+
+  /**
+   * Determines whether this additional field's state should be locked.
+   *
+   * @return bool
+   *   TRUE if a child of this additional field is enabled or the field was
+   *   nevertheless marked as locked, FALSE otherwise.
+   */
+  public function isLocked();
+
 }
diff --git a/src/Item/Field.php b/src/Item/Field.php
index b961d2b..2e2ce9e 100644
--- a/src/Item/Field.php
+++ b/src/Item/Field.php
@@ -53,6 +53,20 @@ class Field implements \IteratorAggregate, FieldInterface {
   protected $boost;
 
   /**
+   * Whether this field should always be enabled/indexed.
+   *
+   * @var bool
+   */
+  protected $indexedLocked;
+
+  /**
+   * Whether this field type should be locked.
+   *
+   * @var bool
+   */
+  protected $typeLocked;
+
+  /**
    * {@inheritdoc}
    */
   public function getType() {
@@ -129,7 +143,7 @@ class Field implements \IteratorAggregate, FieldInterface {
       $fields = $this->index->getOption('fields', array());
       $this->indexed = isset($fields[$this->fieldIdentifier]);
     }
-    return $this->isLocked() || $this->indexed;
+    return $this->isIndexedLocked() || $this->indexed;
   }
 
   /**
@@ -186,6 +200,60 @@ class Field implements \IteratorAggregate, FieldInterface {
   }
 
   /**
+   * Determines whether this field should always be enabled/indexed.
+   *
+   * @return bool
+   *   TRUE if this field should be locked as enabled/indexed.
+   *
+   * @see \Drupal\search_api\Item\GenericFieldInterface::isIndexedLocked()
+   */
+  public function isIndexedLocked() {
+    return (bool) $this->indexedLocked;
+  }
+
+  /**
+   * Sets whether this field should be locked.
+   *
+   * @param bool $indexedLocked
+   *   (optional) TRUE if the field should be locked, FALSE otherwise.
+   *
+   * @return $this
+   *
+   * @see \Drupal\search_api\Item\GenericFieldInterface::setIndexedLocked()
+   */
+  public function setIndexedLocked($indexedLocked = TRUE) {
+    $this->indexedLocked = $indexedLocked;
+    return $this;
+  }
+
+  /**
+   * Determines whether this type of this field should be locked.
+   *
+   * @return bool
+   *   TRUE if type type of this field should be locked.
+   *
+   * @see \Drupal\search_api\Item\GenericFieldInterface::isTypeLocked()
+   */
+  public function isTypeLocked() {
+    return (bool) $this->typeLocked;
+  }
+
+  /**
+   * Sets whether type type of this field should be locked.
+   *
+   * @param bool $typeLocked
+   *   (optional) TRUE if the field should be locked, FALSE otherwise.
+   *
+   * @return $this
+   *
+   * @see \Drupal\search_api\Item\GenericFieldInterface::setTypeLocked()
+   */
+  public function setTypeLocked($typeLocked = TRUE) {
+    $this->typeLocked = $typeLocked;
+    return $this;
+  }
+
+  /**
    * {@inheritdoc}
    */
   public function __sleep() {
diff --git a/src/Item/FieldInterface.php b/src/Item/FieldInterface.php
index c12c5c2..759073d 100644
--- a/src/Item/FieldInterface.php
+++ b/src/Item/FieldInterface.php
@@ -130,4 +130,41 @@ interface FieldInterface extends GenericFieldInterface, \Traversable {
    */
   public function setBoost($boost, $notify = FALSE);
 
+  /**
+   * Determines whether this field should always be enabled/indexed.
+   *
+   * @return bool
+   *   TRUE if this field should be locked as enabled/indexed.
+   */
+  public function isIndexedLocked();
+
+  /**
+   * Sets whether this field should be locked.
+   *
+   * @param bool $indexLocked
+   *   (optional) TRUE if the field should be locked, FALSE otherwise.
+   *
+   * @return $this
+   */
+  public function setIndexedLocked($indexLocked = TRUE);
+
+  /**
+   * Determines whether the type of this field should be locked.
+   *
+   * @return bool
+   *   TRUE if the type of this field should be locked.
+   */
+  public function isTypeLocked();
+
+  /**
+   * Sets whether the type of this field should be locked.
+   *
+   * @param bool $typeLocked
+   *   (optional) TRUE if the type of the field should be locked, FALSE
+   *   otherwise.
+   *
+   * @return $this
+   */
+  public function setTypeLocked($typeLocked = TRUE);
+
 }
diff --git a/src/Item/FieldTrait.php b/src/Item/FieldTrait.php
index e7d29dc..42426ec 100644
--- a/src/Item/FieldTrait.php
+++ b/src/Item/FieldTrait.php
@@ -96,13 +96,6 @@ trait FieldTrait {
   protected $labelPrefix;
 
   /**
-   * Whether this field should always be enabled/indexed.
-   *
-   * @var bool
-   */
-  protected $locked;
-
-  /**
    * Whether this field should be hidden from the user.
    *
    * @var bool
@@ -352,33 +345,6 @@ trait FieldTrait {
   }
 
   /**
-   * Determines whether this field should always be enabled/indexed.
-   *
-   * @return bool
-   *   TRUE if this field should be locked as enabled/indexed.
-   *
-   * @see \Drupal\search_api\Item\GenericFieldInterface::isLocked()
-   */
-  public function isLocked() {
-    return (bool) $this->locked;
-  }
-
-  /**
-   * Sets whether this field should be locked.
-   *
-   * @param bool $locked
-   *   (optional) TRUE if the field should be locked, FALSE otherwise.
-   *
-   * @return $this
-   *
-   * @see \Drupal\search_api\Item\GenericFieldInterface::setLocked()
-   */
-  public function setLocked($locked = TRUE) {
-    $this->locked = $locked;
-    return $this;
-  }
-
-  /**
    * Determines whether this field should be hidden from the user.
    *
    * @return bool
diff --git a/src/Item/GenericFieldInterface.php b/src/Item/GenericFieldInterface.php
index cc0872d..96b1fbf 100644
--- a/src/Item/GenericFieldInterface.php
+++ b/src/Item/GenericFieldInterface.php
@@ -144,24 +144,6 @@ interface GenericFieldInterface {
   public function setLabelPrefix($label_prefix);
 
   /**
-   * Determines whether this field should always be enabled/indexed.
-   *
-   * @return bool
-   *   TRUE if this field should be locked as enabled/indexed.
-   */
-  public function isLocked();
-
-  /**
-   * Sets whether this field should be locked.
-   *
-   * @param bool $locked
-   *   (optional) TRUE if the field should be locked, FALSE otherwise.
-   *
-   * @return $this
-   */
-  public function setLocked($locked = TRUE);
-
-  /**
    * Determines whether this field should be hidden from the user.
    *
    * @return bool
diff --git a/src/Plugin/search_api/processor/AddURL.php b/src/Plugin/search_api/processor/AddURL.php
index 5f47e16..30587a9 100644
--- a/src/Plugin/search_api/processor/AddURL.php
+++ b/src/Plugin/search_api/processor/AddURL.php
@@ -35,7 +35,7 @@ class AddURL extends ProcessorPluginBase {
       'description' => $this->t('A URI where the item can be accessed'),
       'type' => 'uri',
     );
-    $properties['search_api_url'] = BasicProperty::createFromDefinition($definition)->setLocked();
+    $properties['search_api_url'] = BasicProperty::createFromDefinition($definition)->setIndexedLocked()->setTypeLocked();
   }
 
   /**
diff --git a/src/Plugin/search_api/processor/AggregatedFields.php b/src/Plugin/search_api/processor/AggregatedFields.php
index 16064a0..5bd6cc1 100644
--- a/src/Plugin/search_api/processor/AggregatedFields.php
+++ b/src/Plugin/search_api/processor/AggregatedFields.php
@@ -388,7 +388,7 @@ class AggregatedFields extends ProcessorPluginBase {
           'description' => $this->fieldDescription($field, $index_fields),
           'type' => $types[$field['type']],
         );
-        $properties[$field_id] = BasicProperty::createFromDefinition($definition)->setLocked();
+        $properties[$field_id] = BasicProperty::createFromDefinition($definition)->setIndexedLocked()->setTypeLocked();
       }
     }
   }
diff --git a/src/Plugin/search_api/processor/ContentAccess.php b/src/Plugin/search_api/processor/ContentAccess.php
index 580f1b2..7c24c65 100644
--- a/src/Plugin/search_api/processor/ContentAccess.php
+++ b/src/Plugin/search_api/processor/ContentAccess.php
@@ -99,9 +99,9 @@ class ContentAccess extends ProcessorPluginBase {
     if ($datasource) {
       $entity_type = $datasource->getEntityTypeId();
       if (in_array($entity_type, array('node', 'comment'))) {
-        $properties['status'] = ProxyProperty::create($properties['status'])->setLocked();
+        $properties['status'] = ProxyProperty::create($properties['status'])->setIndexedLocked()->setTypeLocked();
         if ($entity_type == 'node') {
-          $properties['uid'] = ProxyProperty::create($properties['uid'])->setLocked();
+          $properties['uid'] = ProxyProperty::create($properties['uid'])->setIndexedLocked()->setTypeLocked();
         }
       }
       return;
@@ -112,7 +112,7 @@ class ContentAccess extends ProcessorPluginBase {
       'description' => $this->t('Data needed to apply node access.'),
       'type' => 'string',
     );
-    $properties['search_api_node_grants'] = BasicProperty::createFromDefinition($definition)->setLocked()->setHidden();
+    $properties['search_api_node_grants'] = BasicProperty::createFromDefinition($definition)->setIndexedLocked()->setTypeLocked()->setHidden();
   }
 
   /**
diff --git a/src/Plugin/search_api/processor/Language.php b/src/Plugin/search_api/processor/Language.php
index 6a30230..a085b56 100644
--- a/src/Plugin/search_api/processor/Language.php
+++ b/src/Plugin/search_api/processor/Language.php
@@ -43,7 +43,7 @@ class Language extends ProcessorPluginBase {
       'label' => $this->t('Item language'),
       'description' => $this->t('The language code of the item'),
     );
-    $properties['search_api_language'] = BasicProperty::createFromDefinition($definition)->setLocked();
+    $properties['search_api_language'] = BasicProperty::createFromDefinition($definition)->setIndexedLocked()->setTypeLocked();
   }
 
   /**
diff --git a/src/Plugin/search_api/processor/RenderedItem.php b/src/Plugin/search_api/processor/RenderedItem.php
index 213e97c..7bc1190 100644
--- a/src/Plugin/search_api/processor/RenderedItem.php
+++ b/src/Plugin/search_api/processor/RenderedItem.php
@@ -223,7 +223,7 @@ class RenderedItem extends ProcessorPluginBase {
       'label' => $this->t('Rendered HTML output'),
       'description' => $this->t('The complete HTML which would be displayed when viewing the item'),
     );
-    $properties['rendered_item'] = BasicProperty::createFromDefinition($definition)->setLocked();
+    $properties['rendered_item'] = BasicProperty::createFromDefinition($definition)->setIndexedLocked()->setTypeLocked();
   }
 
   /**
diff --git a/src/Property/PropertyInterface.php b/src/Property/PropertyInterface.php
index fd3e1ad..a5fad02 100644
--- a/src/Property/PropertyInterface.php
+++ b/src/Property/PropertyInterface.php
@@ -15,12 +15,20 @@ use Drupal\Core\TypedData\DataDefinitionInterface;
 interface PropertyInterface extends DataDefinitionInterface {
 
   /**
-   * Determines whether this processor should always be enabled.
+   * Determines whether the indexed property should be locked for the processor.
    *
    * @return bool
-   *   TRUE if this processor should be forced enabled; FALSE otherwise.
+   *   TRUE if this indexed property should be locked; FALSE otherwise.
    */
-  public function isLocked();
+  public function isIndexedLocked();
+
+  /**
+   * Determines whether the type property should be locked for the processor.
+   *
+   * @return bool
+   *   TRUE if the type should be locked; FALSE otherwise.
+   */
+  public function isTypeLocked();
 
   /**
    * Determines whether this processor should be hidden from the user.
diff --git a/src/Property/PropertyTrait.php b/src/Property/PropertyTrait.php
index e05e9c6..12efb6e 100644
--- a/src/Property/PropertyTrait.php
+++ b/src/Property/PropertyTrait.php
@@ -14,11 +14,18 @@ namespace Drupal\search_api\Property;
 trait PropertyTrait {
 
   /**
-   * The locked state of the property.
+   * The locked state of the indexed property.
    *
    * @var bool
    */
-  protected $locked = FALSE;
+  protected $indexedLocked = FALSE;
+
+  /**
+   * The locked state of the type property.
+   *
+   * @var bool
+   */
+  protected $typeLocked = FALSE;
 
   /**
    * The hidden state of the property.
@@ -35,28 +42,53 @@ trait PropertyTrait {
   protected $fieldSettings = array();
 
   /**
-   * Sets the locked state.
+   * Sets the indexed locked state for the property.
+   *
+   * @param bool $indexedLocked
+   *   (optional) The new indexed locked state for the property.
+   *
+   * @return $this
+   */
+  public function setIndexedLocked($indexedLocked = TRUE) {
+    $this->indexedLocked = $indexedLocked;
+    return $this;
+  }
+
+  /**
+   * Determines whether the indexed property should be locked for the processor.
+   *
+   * @return bool
+   *   TRUE if this indexed property should be locked; FALSE otherwise.
+   *
+   * @see \Drupal\search_api\Property\PropertyInterface::isIndexLocked()
+   */
+  public function isIndexedLocked() {
+    return $this->indexedLocked;
+  }
+
+  /**
+   * Sets the type locked state for the property.
    *
-   * @param bool $locked
-   *   (optional) The new locked state.
+   * @param bool $typeLocked
+   *   (optional) The new type locked state for the property.
    *
    * @return $this
    */
-  public function setLocked($locked = TRUE) {
-    $this->locked = $locked;
+  public function setTypeLocked($typeLocked = TRUE) {
+    $this->typeLocked = $typeLocked;
     return $this;
   }
 
   /**
-   * Determines whether this processor should always be enabled.
+   * Determines whether the type property should be locked for the processor.
    *
    * @return bool
-   *   TRUE if this processor should be forced enabled; FALSE otherwise.
+   *   TRUE if the type should be locked; FALSE otherwise.
    *
-   * @see \Drupal\search_api\Property\PropertyInterface::isLocked()
+   * @see \Drupal\search_api\Property\PropertyInterface::isIndexLocked()
    */
-  public function isLocked() {
-    return $this->locked;
+  public function isTypeLocked() {
+    return $this->typeLocked;
   }
 
   /**