diff --git a/core/includes/config.inc b/core/includes/config.inc
index 26f4b6f..c143dd4 100644
--- a/core/includes/config.inc
+++ b/core/includes/config.inc
@@ -91,13 +91,13 @@ function config_sync_get_changes(StorageInterface $source_storage, StorageInterf
   foreach (array_intersect($source_names, $target_names) as $name) {
     $source_config_data = $source_storage->read($name);
     $target_config_data = $target_storage->read($name);
-    if ($source_config_data != $target_config_data) {
+    if ($source_config_data !== $target_config_data) {
       $config_changes['change'][] = $name;
     }
   }
 
   // Do not trigger subsequent synchronization operations if there are no
-  // changes in either category.
+  // changes in any category.
   if (empty($config_changes['create']) && empty($config_changes['change']) && empty($config_changes['delete'])) {
     return FALSE;
   }
@@ -130,6 +130,10 @@ function config_sync_changes(array $config_changes, StorageInterface $source_sto
 
 /**
  * Imports configuration from FileStorage to DatabaseStorage.
+ *
+ * @return bool|null
+ *   TRUE if configuration was imported successfully, FALSE in case of a
+ *   synchronization error, or NULL if there are no changes to synchronize.
  */
 function config_import() {
   // Retrieve a list of differences between FileStorage and DatabaseStorage.
@@ -144,14 +148,14 @@ function config_import() {
 
   if (!lock_acquire(__FUNCTION__)) {
     // Another request is synchronizing configuration.
-    // Return a negative result for UI purposes. We do not make a difference
-    // between an actual synchronization error and a failed lock, because a
-    // concurrent request synchronizing configuration is an edge-case in the
-    // first place and would mean that more than one developer or site builder
-    // attempts to do it without coordinating with others.
+    // Return a negative result for UI purposes. We do not differentiate between
+    // an actual synchronization error and a failed lock, because concurrent
+    // synchronizations are an edge-case happening only when multiple developers
+    // or site builders attempt to do it without coordinating.
     return FALSE;
   }
 
+  $success = TRUE;
   try {
     $remaining_changes = config_import_invoke_owner($config_changes, $source_storage, $target_storage);
     config_sync_changes($remaining_changes, $source_storage, $target_storage);
@@ -160,11 +164,10 @@ function config_import() {
   }
   catch (ConfigException $e) {
     watchdog_exception('config_import', $e);
-    lock_release(__FUNCTION__);
-    return FALSE;
+    $success = FALSE;
   }
   lock_release(__FUNCTION__);
-  return TRUE;
+  return $success;
 }
 
 /**