diff --git a/core/lib/Drupal/Core/Entity/Schema/ContentEntitySchemaHandler.php b/core/lib/Drupal/Core/Entity/Schema/ContentEntitySchemaHandler.php
index 22947946e0d..4f30d47f7ab 100644
--- a/core/lib/Drupal/Core/Entity/Schema/ContentEntitySchemaHandler.php
+++ b/core/lib/Drupal/Core/Entity/Schema/ContentEntitySchemaHandler.php
@@ -240,7 +240,7 @@ class ContentEntitySchemaHandler implements EntitySchemaHandlerInterface {
       // field name to avoid clashes when multiple fields of the same type are
       // added to an entity type.
       $entity_type_id = $this->entityType->id();
-      $real_key = "{$entity_type_id}_field__{$field_name}__{$key}";
+      $real_key = $this->getFieldSchemaIdentifierName($entity_type_id, $field_name, $key);
       foreach ($columns as $column) {
         // Allow for indexes and unique keys to specified as an array of column
         // name and length.
@@ -257,6 +257,34 @@ class ContentEntitySchemaHandler implements EntitySchemaHandlerInterface {
     return $data;
   }
 
+  /**
+   * Generates a safe schema identifier (name of an index, column name etc.).
+   *
+   * @param string $entity_type_id
+   *   The ID of the entity type.
+   * @param string $field_name
+   *   The name of the field.
+   * @param string $key
+   *   The key of the field.
+   *
+   * @return string
+   *   The field identifier name.
+   */
+  protected function getFieldSchemaIdentifierName($entity_type_id, $field_name, $key) {
+    $real_key = "{$entity_type_id}_field__{$field_name}__{$key}";
+    // Limit the string to 48 characters, keeping a 16 characters margin for db
+    // prefixes.
+    if (strlen($real_key) > 48) {
+      // Use a shorter separator, a truncated entity_type, and a hash of the
+      // field name.
+      // Truncate to the same length for the current and revision tables.
+      $entity_type = substr($entity_type_id, 0, 36);
+      $field_hash = substr(hash('sha256', $real_key), 0, 10);
+      $real_key = $entity_type . '__' . $field_hash;
+    }
+    return $real_key;
+  }
+
   /**
    * Returns field foreign keys.
    *
diff --git a/core/tests/Drupal/Tests/Core/Entity/Schema/ContentEntitySchemaHandlerTest.php b/core/tests/Drupal/Tests/Core/Entity/Schema/ContentEntitySchemaHandlerTest.php
index 83b3509266a..f6f4959551f 100644
--- a/core/tests/Drupal/Tests/Core/Entity/Schema/ContentEntitySchemaHandlerTest.php
+++ b/core/tests/Drupal/Tests/Core/Entity/Schema/ContentEntitySchemaHandlerTest.php
@@ -234,6 +234,17 @@ class ContentEntitySchemaHandlerTest extends UnitTestCase {
         ),
       ),
     ));
+    // Add a field with a really long index.
+    $this->setUpStorageDefinition('long_index_name', array(
+      'columns' => array(
+        'long_index_name' => array(
+          'type' => 'int',
+        ),
+      ),
+      'indexes' => array(
+        'long_index_name_really_long_long_name' => array(array('long_index_name', 10)),
+      ),
+    ));
 
     $this->setUpSchemaHandler();
 
@@ -321,6 +332,10 @@ class ContentEntitySchemaHandlerTest extends UnitTestCase {
             'description' => 'The editor_revision field.',
             'type' => 'int',
           ),
+          'long_index_name' => array(
+            'description' => 'The long_index_name field.',
+            'type' => 'int',
+          ),
           'default_langcode' => array(
             'description' => 'Boolean indicating whether field values are in the default entity language.',
             'type' => 'int',
@@ -349,6 +364,10 @@ class ContentEntitySchemaHandlerTest extends UnitTestCase {
             'location__state',
             array('location__city', 10),
           ),
+          'entity_test__b588603cb9' => array(
+            array('long_index_name', 10),
+          ),
+
         ),
         'foreign keys' => array(
           'entity_test_field__editor__user_id' => array(