diff --git a/src/Entity/Index.php b/src/Entity/Index.php
index 88148a5..672bb37 100644
--- a/src/Entity/Index.php
+++ b/src/Entity/Index.php
@@ -1489,6 +1489,8 @@ class Index extends ConfigEntityBase implements IndexInterface {
     }
     foreach ($this->getProcessors() as $processor) {
       $this->calculatePluginDependencies($processor);
+      $processor_dependencies = $processor->calculateDependencies();
+      $this->dependencies += $processor_dependencies;
     }
     foreach ($this->getDatasources() as $datasource) {
       $this->calculatePluginDependencies($datasource);
@@ -1525,6 +1527,15 @@ class Index extends ConfigEntityBase implements IndexInterface {
     }
     $this->setOption('processors', $processors);
 
+    // Make sure that all enabled processors are notified about the dependencies
+    // that will suddenly be removed and give it time to react to that.
+    foreach ($this->getProcessors() as $processor) {
+      $is_processor_changed = $processor->onDependencyRemoval($this, $dependencies);
+      if ($is_processor_changed) {
+        $changed = TRUE;
+      }
+    }
+
     return $changed;
   }
 
diff --git a/src/Processor/ProcessorInterface.php b/src/Processor/ProcessorInterface.php
index 707232d..90d4d49 100644
--- a/src/Processor/ProcessorInterface.php
+++ b/src/Processor/ProcessorInterface.php
@@ -174,4 +174,17 @@ interface ProcessorInterface extends IndexPluginInterface {
    */
   public function requiresReindexing(array $old_settings = NULL, array $new_settings = NULL);
 
+  /**
+   * Informs the plugin that entities it depends on will be deleted.
+   *
+   * @param \Drupal\search_api\IndexInterface $index
+   *   The index we're being removed from.
+   * @param array $dependencies
+   *   An array of dependencies
+   *
+   * @return bool
+   *   Has something changed?
+   */
+  public function onDependencyRemoval(IndexInterface $index, array $dependencies);
+
 }
diff --git a/src/Processor/ProcessorPluginBase.php b/src/Processor/ProcessorPluginBase.php
index f873d62..fbb309b 100644
--- a/src/Processor/ProcessorPluginBase.php
+++ b/src/Processor/ProcessorPluginBase.php
@@ -111,4 +111,13 @@ abstract class ProcessorPluginBase extends IndexPluginBase implements ProcessorI
     // indexing process.
     return $this->supportsStage(ProcessorInterface::STAGE_PREPROCESS_INDEX);
   }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function onDependencyRemoval(IndexInterface $index, array $dependencies) {
+    // By default, we're not reacting to anything and so we should leave
+    // everything as it was.
+    return FALSE;
+  }
 }
diff --git a/src/Tests/DependencyRemovalTest.php b/src/Tests/DependencyRemovalTest.php
index f0f082d..b68fb11 100644
--- a/src/Tests/DependencyRemovalTest.php
+++ b/src/Tests/DependencyRemovalTest.php
@@ -7,6 +7,8 @@
 
 namespace Drupal\search_api\Tests;
 
+use Drupal\Core\Entity\Entity\EntityViewMode;
+
 /**
  * Tests what happens when an index's dependencies are removed.
  *
@@ -62,6 +64,28 @@ class DependencyRemovalTest extends WebTestBase {
   }
 
   /**
+   * Tests what happens when a processors dependencies are removed.
+   *
+   * This is in a seperate test, because we need the search_api_test_processor enabled.
+   */
+  public function testProcessorDependencyRemoval() {
+    EntityViewMode::create(array('id' =>  'node.teaser_test', 'targetEntityType' => 'node'))->save();
+
+    $this->drupalGet($this->getIndexPath('processors'));
+    $this->assertText($this->t('Dependency test processor'));
+    $this->drupalPostForm(NULL, array('status[dependency_test_processor]' => 1), $this->t('Save'));
+    $this->assertResponse(200);
+    $this->assertText($this->t('The indexing workflow was successfully edited.'));
+
+    $evm = EntityViewMode::load('node.teaser_test');
+    $evm->delete();
+
+    // The index was removed, because the entity view mode was removed.
+    $this->drupalGet($this->getIndexPath());
+    $this->assertResponse(404);
+  }
+
+  /**
    * Tests the reaction of an index when a processor's module is removed.
    *
    * When a module that provides a processor is uninstalled, it should not
diff --git a/tests/search_api_test_processor/config/schema/search_api_test_processor.schema.yml b/tests/search_api_test_processor/config/schema/search_api_test_processor.schema.yml
index a9c5c2c..edeee3e 100644
--- a/tests/search_api_test_processor/config/schema/search_api_test_processor.schema.yml
+++ b/tests/search_api_test_processor/config/schema/search_api_test_processor.schema.yml
@@ -8,3 +8,14 @@ plugin.plugin_configuration.search_api_processor.dummy_processor:
       sequence:
         type: string
         label: 'Selected field'
+
+plugin.plugin_configuration.search_api_processor.dependency_test_processor:
+  type: mapping
+  label: 'Dummy processor configuration'
+  mapping:
+    fields:
+      type: sequence
+      label: 'The selected fields'
+      sequence:
+        type: string
+        label: 'Selected field'
diff --git a/tests/search_api_test_processor/src/Plugin/search_api/processor/DependencyTestProcessor.php b/tests/search_api_test_processor/src/Plugin/search_api/processor/DependencyTestProcessor.php
new file mode 100644
index 0000000..6e827ab
--- /dev/null
+++ b/tests/search_api_test_processor/src/Plugin/search_api/processor/DependencyTestProcessor.php
@@ -0,0 +1,71 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\search_api_test_processor\Plugin\search_api\processor\DependencyTestProcessor.
+ */
+
+namespace Drupal\search_api_test_processor\Plugin\search_api\processor;
+
+use Drupal\Core\Entity\Entity\EntityViewMode;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Plugin\PluginDependencyTrait;
+use Drupal\search_api\IndexInterface;
+use Drupal\search_api\Processor\FieldsProcessorPluginBase;
+
+/**
+ * @SearchApiProcessor(
+ *   id = "dependency_test_processor",
+ *   label = @Translation("Dependency test processor"),
+ *   description = @Translation("Makes dummy operations."),
+ *   stages = {
+ *     "preprocess_index" = -20,
+ *     "preprocess_query" = -20
+ *   }
+ * )
+ */
+class DependencyTestProcessor extends FieldsProcessorPluginBase {
+
+  use PluginDependencyTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function process(&$value) {
+    // We don't touch integers, NULL values or the like.
+    if (is_string($value)) {
+      $value .= ' test processor touched this';
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
+    $form = parent::buildConfigurationForm($form, $form_state);
+
+    /** @var \Drupal\Core\Entity\Entity\EntityViewMode $evm */
+    $evm = EntityViewMode::load('node.teaser_test');
+
+    if ($evm !== null) {
+      $this->addDependency('config', $evm->getEntityType()->getConfigPrefix() . '.' . $evm->id());
+    }
+
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function calculateDependencies() {
+    return $this->dependencies;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function onDependencyRemoval(IndexInterface $index, array $dependencies) {
+    return FALSE;
+  }
+
+}