diff --git a/core/modules/field/lib/Drupal/field/Plugin/Core/Entity/Field.php b/core/modules/field/lib/Drupal/field/Plugin/Core/Entity/Field.php
index 4b3a04d..cf57104 100644
--- a/core/modules/field/lib/Drupal/field/Plugin/Core/Entity/Field.php
+++ b/core/modules/field/lib/Drupal/field/Plugin/Core/Entity/Field.php
@@ -444,8 +444,18 @@ public function getSchema() {
     if (!isset($this->schema)) {
       // Get the schema from the field item class.
       $definition = \Drupal::typedData()->getDefinition('field_type:' . $this->type);
-      $class = $definition['class'];
-      $schema = $class::schema($this);
+      // @todo BC layer schema not found, especially during install (image).
+      if (!empty($definition['class'])) {
+        $class = $definition['class'];
+        $schema = $class::schema($this);
+      }
+      else {
+        $module_handler = \Drupal::moduleHandler();
+        module_load_install($this->module);
+        // Invoke hook_field_schema() for the field.
+        $schema = (array) $module_handler->invoke($this->module, 'field_schema', array($this));
+        $schema += array('columns' => array(), 'indexes' => array(), 'foreign keys' => array());
+      }
       // Fill in default values for optional entries.
       $schema += array('indexes' => array(), 'foreign keys' => array());