diff --git a/core/lib/Drupal/Core/Config/FileStorage.php b/core/lib/Drupal/Core/Config/FileStorage.php
index 03b0464..382733c 100644
--- a/core/lib/Drupal/Core/Config/FileStorage.php
+++ b/core/lib/Drupal/Core/Config/FileStorage.php
@@ -207,8 +207,9 @@ public function listAll($prefix = '') {
     $files = scandir($dir);
 
     $names = array();
+    $pattern = '/^' . preg_quote($prefix, '/') . '.*' . preg_quote($extension, '/') . '$/';
     foreach ($files as $file) {
-      if ($file[0] !== '.' && fnmatch($prefix . '*' . $extension, $file)) {
+      if ($file[0] !== '.' && preg_match($pattern, $file)) {
         $names[] = basename($file, $extension);
       }
     }
@@ -290,6 +291,7 @@ public function getAllCollectionNames() {
    */
   protected function getAllCollectionNamesHelper($directory) {
     $collections = array();
+    $pattern = '/\.' . preg_quote($this->getFileExtension(), '/') . '$/';
     foreach (new \DirectoryIterator($directory) as $fileinfo) {
       if ($fileinfo->isDir() && !$fileinfo->isDot()) {
         $collection = $fileinfo->getFilename();
@@ -309,7 +311,7 @@ protected function getAllCollectionNamesHelper($directory) {
         // collection.
         // @see \Drupal\Core\Config\FileStorage::listAll()
         foreach (scandir($directory . '/' . $collection) as $file) {
-          if ($file[0] !== '.' && fnmatch('*.' . $this->getFileExtension(), $file)) {
+          if ($file[0] !== '.' && preg_match($pattern, $file)) {
             $collections[] = $collection;
             break;
           }
diff --git a/core/lib/Drupal/Core/Config/InstallStorage.php b/core/lib/Drupal/Core/Config/InstallStorage.php
index ca96bd7..5f70cd9 100644
--- a/core/lib/Drupal/Core/Config/InstallStorage.php
+++ b/core/lib/Drupal/Core/Config/InstallStorage.php
@@ -190,6 +190,7 @@ protected function getAllFolders() {
    */
   public function getComponentNames(array $list) {
     $extension = '.' . $this->getFileExtension();
+    $pattern = '/' . preg_quote($extension, '/') . '$/';
     $folders = array();
     foreach ($list as $extension_object) {
       // We don't have to use ExtensionDiscovery here because our list of
@@ -203,7 +204,7 @@ public function getComponentNames(array $list) {
         $files = scandir($directory);
 
         foreach ($files as $file) {
-          if ($file[0] !== '.' && fnmatch('*' . $extension, $file)) {
+          if ($file[0] !== '.' && preg_match($pattern, $file)) {
             $folders[basename($file, $extension)] = $directory;
           }
         }
@@ -220,6 +221,7 @@ public function getComponentNames(array $list) {
    */
   public function getCoreNames() {
     $extension = '.' . $this->getFileExtension();
+    $pattern = '/' . preg_quote($extension, '/') . '$/';
     $folders = array();
     $directory = $this->getCoreFolder();
     if (is_dir($directory)) {
@@ -230,7 +232,7 @@ public function getCoreNames() {
       $files = scandir($directory);
 
       foreach ($files as $file) {
-        if ($file[0] !== '.' && fnmatch('*' . $extension, $file)) {
+        if ($file[0] !== '.' && preg_match($pattern, $file)) {
           $folders[basename($file, $extension)] = $directory;
         }
       }
diff --git a/core/modules/ckeditor/src/Plugin/Editor/CKEditor.php b/core/modules/ckeditor/src/Plugin/Editor/CKEditor.php
index 8072060..f84054c 100644
--- a/core/modules/ckeditor/src/Plugin/Editor/CKEditor.php
+++ b/core/modules/ckeditor/src/Plugin/Editor/CKEditor.php
@@ -335,7 +335,7 @@ public function getLangcodes() {
       // Collect languages included with CKEditor based on file listing.
       $files = scandir('core/assets/vendor/ckeditor/lang');
       foreach ($files as $file) {
-        if ($file[0] !== '.' && fnmatch('*.js', $file)) {
+        if ($file[0] !== '.' && preg_match('/\.js$/', $file)) {
           $langcode = basename($file, '.js');
           $langcodes[$langcode] = $langcode;
         }
diff --git a/core/modules/config/src/Tests/Storage/FileStorageTest.php b/core/modules/config/src/Tests/Storage/FileStorageTest.php
index fb17f1e..a37f084 100644
--- a/core/modules/config/src/Tests/Storage/FileStorageTest.php
+++ b/core/modules/config/src/Tests/Storage/FileStorageTest.php
@@ -70,6 +70,12 @@ public function testlistAll() {
     $config_files = $this->storage->listAll();
     $this->assertIdentical($config_files, $expected_files, 'Relative path, two config files found.');
 
+    // @todo https://www.drupal.org/node/2666954 FileStorage::listAll() is
+    //   case-sensitive. However, \Drupal\Core\Config\DatabaseStorage::listAll()
+    //   is case-insensitive.
+    $this->assertIdentical(['system.performance'], $this->storage->listAll('system'), 'The FileStorage::listAll() with prefix works.');
+    $this->assertIdentical([], $this->storage->listAll('System'), 'The FileStorage::listAll() is case sensitive.');
+
     // Initialize FileStorage with absolute file path.
     $absolute_path = realpath($this->directory);
     $storage_absolute_path = new FileStorage($absolute_path);
diff --git a/core/modules/migrate/src/MigrateTemplateStorage.php b/core/modules/migrate/src/MigrateTemplateStorage.php
index 7124d57..8467ad6 100644
--- a/core/modules/migrate/src/MigrateTemplateStorage.php
+++ b/core/modules/migrate/src/MigrateTemplateStorage.php
@@ -74,7 +74,7 @@ public function getAllTemplates() {
       if (file_exists($full_directory)) {
         $files = scandir($full_directory);
         foreach ($files as $file) {
-          if ($file[0] !== '.' && fnmatch('*.yml', $file)) {
+          if ($file[0] !== '.' && preg_match('/\.yml$/', $file)) {
             $templates[basename($file, '.yml')] = Yaml::decode(file_get_contents("$full_directory/$file"));
           }
         }