diff --git a/core/lib/Drupal/Core/KeyValueStore/DatabaseStorage.php b/core/lib/Drupal/Core/KeyValueStore/DatabaseStorage.php
index fe71c47..4954a52 100644
--- a/core/lib/Drupal/Core/KeyValueStore/DatabaseStorage.php
+++ b/core/lib/Drupal/Core/KeyValueStore/DatabaseStorage.php
@@ -267,7 +267,7 @@ protected function catchException(\Exception $e) {
   /**
    * Defines the schema for the key_value table.
    */
-  public function schemaDefinition() {
+  public static function schemaDefinition() {
     return [
       'description' => 'Generic key-value storage table. See the state system for an example.',
       'fields' => [
diff --git a/core/lib/Drupal/Core/KeyValueStore/DatabaseStorageExpirable.php b/core/lib/Drupal/Core/KeyValueStore/DatabaseStorageExpirable.php
index 1b09812..64397f2 100644
--- a/core/lib/Drupal/Core/KeyValueStore/DatabaseStorageExpirable.php
+++ b/core/lib/Drupal/Core/KeyValueStore/DatabaseStorageExpirable.php
@@ -171,7 +171,7 @@ public function deleteMultiple(array $keys) {
   /**
    * Defines the schema for the key_value_expire table.
    */
-  public function schemaDefinition() {
+  public static function schemaDefinition() {
     return [
       'description' => 'Generic key/value storage table with an expiration.',
       'fields' => [