diff --git a/includes/file.inc b/includes/file.inc
index 08c3053a826..fe2bd480780 100644
--- a/includes/file.inc
+++ b/includes/file.inc
@@ -2749,7 +2749,7 @@ function file_uri_normalize_dot_segments($uri) {
     if ($target !== FALSE) {
       if (!in_array($scheme, variable_get('file_sa_core_2023_005_schemes', array()))) {
         $class = file_stream_wrapper_get_class($scheme);
-        $is_local = is_subclass_of($class, DrupalLocalStreamWrapper::class);
+        $is_local = is_subclass_of($class, 'DrupalLocalStreamWrapper');
         if ($is_local) {
           $target = str_replace(DIRECTORY_SEPARATOR, '/', $target);
         }
diff --git a/modules/system/system.module b/modules/system/system.module
index 5522b86ff28..af71f29dd3d 100644
--- a/modules/system/system.module
+++ b/modules/system/system.module
@@ -4100,7 +4100,7 @@ function system_file_download($uri) {
       if (!in_array($scheme, variable_get('file_sa_core_2023_005_schemes', array()))) {
         if (DIRECTORY_SEPARATOR !== '/') {
           $class = file_stream_wrapper_get_class($scheme);
-          if (is_subclass_of($class, DrupalLocalStreamWrapper::class)) {
+          if (is_subclass_of($class, 'DrupalLocalStreamWrapper')) {
             $target = str_replace(DIRECTORY_SEPARATOR, '/', $target);
           }
         }