diff --git a/core/includes/module.inc b/core/includes/module.inc
index f65f0b8..79e382d 100644
--- a/core/includes/module.inc
+++ b/core/includes/module.inc
@@ -179,10 +179,12 @@ function drupal_required_modules() {
 function module_set_weight($module, $weight) {
   $extension_config = \Drupal::configFactory()->getEditable('core.extension');
   if ($extension_config->get("module.$module") !== NULL) {
+    // Pre-cast the $weight to an integer so that we can save this without using
+    // schema. This is a performance improvement for module installation.
     $extension_config
-      ->set("module.$module", $weight)
+      ->set("module.$module", (int) $weight)
       ->set('module', module_config_sort($extension_config->get('module')))
-      ->save();
+      ->save(TRUE);
 
     // Prepare the new module list, sorted by weight, including filenames.
     // @see \Drupal\Core\Extension\ModuleHandler::install()
diff --git a/core/lib/Drupal/Core/Extension/ModuleInstaller.php b/core/lib/Drupal/Core/Extension/ModuleInstaller.php
index 156a16c..8e5e0c3 100644
--- a/core/lib/Drupal/Core/Extension/ModuleInstaller.php
+++ b/core/lib/Drupal/Core/Extension/ModuleInstaller.php
@@ -155,10 +155,12 @@ public function install(array $module_list, $enable_dependencies = TRUE) {
         // exceptions if the configuration is not valid.
         $config_installer->checkConfigurationToInstall('module', $module);
 
+        // Save this data without checking schema. This is a performance
+        // improvement for module installation.
         $extension_config
           ->set("module.$module", 0)
           ->set('module', module_config_sort($extension_config->get('module')))
-          ->save();
+          ->save(TRUE);
 
         // Prepare the new module list, sorted by weight, including filenames.
         // This list is used for both the ModuleHandler and DrupalKernel. It
@@ -382,8 +384,9 @@ public function uninstall(array $module_list, $uninstall_dependents = TRUE) {
       // Remove the schema.
       drupal_uninstall_schema($module);
 
-      // Remove the module's entry from the config.
-      \Drupal::configFactory()->getEditable('core.extension')->clear("module.$module")->save();
+      // Remove the module's entry from the config. Don't check schema when
+      // uninstalling a module since we are only clearing a key.
+      \Drupal::configFactory()->getEditable('core.extension')->clear("module.$module")->save(TRUE);
 
       // Update the module handler to remove the module.
       // The current ModuleHandler instance is obsolete with the kernel rebuild
diff --git a/core/lib/Drupal/Core/Extension/ThemeHandler.php b/core/lib/Drupal/Core/Extension/ThemeHandler.php
index 57a317e..9d790ae 100644
--- a/core/lib/Drupal/Core/Extension/ThemeHandler.php
+++ b/core/lib/Drupal/Core/Extension/ThemeHandler.php
@@ -260,10 +260,11 @@ public function install(array $theme_list, $install_dependencies = TRUE) {
       // configuration then stop installing.
       $this->configInstaller->checkConfigurationToInstall('theme', $key);
 
-      // The value is not used; the weight is ignored for themes currently.
+      // The value is not used; the weight is ignored for themes currently. Do
+      // not check schema when saving the configuration.
       $extension_config
         ->set("theme.$key", 0)
-        ->save();
+        ->save(TRUE);
 
       // Add the theme to the current list.
       // @todo Remove all code that relies on $status property.
@@ -358,7 +359,9 @@ public function uninstall(array $theme_list) {
       $this->configManager->uninstall('theme', $key);
 
     }
-    $extension_config->save();
+    // Don't check schema when uninstalling a theme since we are only clearing
+    // keys.
+    $extension_config->save(TRUE);
     $this->state->set('system.theme.data', $current_theme_data);
 
     $this->resetSystem();