diff --git a/core/includes/schema.inc b/core/includes/schema.inc
index 59c79c0..40ca702 100644
--- a/core/includes/schema.inc
+++ b/core/includes/schema.inc
@@ -139,13 +139,13 @@ function drupal_get_schema_versions($module) {
       }
     }
     // Ensure that updates are applied in numerical order.
-    foreach ($updates as $module => &$module_updates) {
+    foreach ($updates as $module_name => &$module_updates) {
       // No module is allowed to define a schema update of exactly
       // \Drupal::CORE_MINIMUM_SCHEMA_VERSION because this is reserved for the
       // minimum installed version.
       if (in_array(\Drupal::CORE_MINIMUM_SCHEMA_VERSION, $module_updates)) {
-        throw new ExtensionSchemaVersionException(format_string("%module's hook_update_N() implementations must use N greater than @version.", array(
-          '%module' => $module,
+        throw new ExtensionSchemaVersionException(format_string("%module_name's hook_update_N() implementations must use N greater than @version.", array(
+          '%module_name' => $module_name,
           '@version' => \Drupal::CORE_MINIMUM_SCHEMA_VERSION,
         )));
       }
diff --git a/core/includes/update.inc b/core/includes/update.inc
index 0649254..ba5242b 100644
--- a/core/includes/update.inc
+++ b/core/includes/update.inc
@@ -147,7 +147,7 @@ function update_prepare_d8_bootstrap() {
   catch (\Exception $e) {
     $system_schema = db_query('SELECT schema_version FROM {system} WHERE name = :system', array(':system' => 'system'))->fetchField();
   }
-  if ($system_schema < \Drupal::MINIMUM_CORE_SCHEMA_VERSION) {
+  if ($system_schema < \Drupal::CORE_MINIMUM_SCHEMA_VERSION) {
     $requirements = array(
       'drupal 7 version' => array(
         'title' => 'Drupal 7 version',
diff --git a/core/modules/system/lib/Drupal/system/Tests/Update/UpdateScriptTest.php b/core/modules/system/lib/Drupal/system/Tests/Update/UpdateScriptTest.php
index b09b30b..65d9224 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Update/UpdateScriptTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Update/UpdateScriptTest.php
@@ -165,7 +165,10 @@ function testNoUpdateFunctionality() {
    * Tests update.php after performing a successful update.
    */
   function testSuccessfulUpdateFunctionality() {
-    drupal_set_installed_schema_version('update_script_test', drupal_get_installed_schema_version('update_script_test') - 1);
+    // Set the installed schema version to one less than the current update.
+    // Reset the static cache to ensure we have the most current setting.
+    drupal_set_installed_schema_version('update_script_test', drupal_get_installed_schema_version('update_script_test', TRUE) - 1);
+
     // Click through update.php with 'administer software updates' permission.
     $this->drupalLogin($this->update_user);
     $this->drupalPostForm($this->update_url, array(), t('Continue'), array('external' => TRUE));
@@ -178,7 +181,10 @@ function testSuccessfulUpdateFunctionality() {
     $this->clickLink('Front page');
     $this->assertResponse(200);
 
-    drupal_set_installed_schema_version('update_script_test', drupal_get_installed_schema_version('update_script_test') - 1);
+    // Set the installed schema version to one less than the current update.
+    // Reset the static cache to ensure we have the most current setting.
+    drupal_set_installed_schema_version('update_script_test', drupal_get_installed_schema_version('update_script_test', TRUE) - 1);
+
     // Click through update.php with 'access administration pages' and
     // 'access site reports' permissions.
     $admin_user = $this->drupalCreateUser(array('administer software updates', 'access administration pages', 'access site reports'));
diff --git a/core/modules/system/system.install b/core/modules/system/system.install
index d99b6a0..c6ad793 100644
--- a/core/modules/system/system.install
+++ b/core/modules/system/system.install
@@ -1161,3 +1161,18 @@ function system_schema() {
 function system_update_last_removed() {
   return 7069;
 }
+
+/**
+ * @todo Remove.
+ */
+function system_update_8001() {}
+
+/**
+ * @todo Remove.
+ */
+function system_update_8002() {}
+
+/**
+ * @todo Remove.
+ */
+function system_update_8003() {}