core/modules/system/tests/src/Kernel/Action/ActionTest.php | 1 +
 core/modules/update/config/install/update.settings.yml     | 2 +-
 core/modules/update/config/schema/update.schema.yml        | 1 +
 3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/core/modules/system/tests/src/Kernel/Action/ActionTest.php b/core/modules/system/tests/src/Kernel/Action/ActionTest.php
index becf628e64..9bac28f573 100644
--- a/core/modules/system/tests/src/Kernel/Action/ActionTest.php
+++ b/core/modules/system/tests/src/Kernel/Action/ActionTest.php
@@ -34,6 +34,7 @@ protected function setUp(): void {
 
     $this->actionManager = $this->container->get('plugin.manager.action');
     $this->installEntitySchema('user');
+    $this->installConfig(['user']);
     $this->installSchema('system', ['sequences']);
   }
 
diff --git a/core/modules/update/config/install/update.settings.yml b/core/modules/update/config/install/update.settings.yml
index ded8c9d24c..2e4f3fb314 100644
--- a/core/modules/update/config/install/update.settings.yml
+++ b/core/modules/update/config/install/update.settings.yml
@@ -2,7 +2,7 @@ check:
   disabled_extensions: false
   interval_days: 1
 fetch:
-  url: ''
+  url: ~
   max_attempts: 2
   timeout: 30
 notification:
diff --git a/core/modules/update/config/schema/update.schema.yml b/core/modules/update/config/schema/update.schema.yml
index e9da9268e7..06eeb49c36 100644
--- a/core/modules/update/config/schema/update.schema.yml
+++ b/core/modules/update/config/schema/update.schema.yml
@@ -20,6 +20,7 @@ update.settings:
       mapping:
         url:
           type: uri
+          nullable: true
           label: 'URL for fetching available update data'
         max_attempts:
           type: integer