diff --git a/src/Form/FillPdfSettingsForm.php b/src/Form/FillPdfSettingsForm.php
index e5d45a7064288e59089354e4d37a56aa7c20d34c..dbdb5845a08b2b0bda835482c1d97fd8128a62bf 100644
--- a/src/Form/FillPdfSettingsForm.php
+++ b/src/Form/FillPdfSettingsForm.php
@@ -148,7 +148,7 @@ class FillPdfSettingsForm extends ConfigFormBase {
       '#type' => 'details',
       '#title' => $this->t('Advanced storage settings'),
     ];
-    $file_default_scheme = file_default_scheme();
+    $file_default_scheme = $this->config('system.file')->get('default_scheme');
     $template_scheme_options = $this->adminFormHelper->schemeOptions([
       $file_default_scheme => $this->t('@scheme (site default)'),
     ]);
diff --git a/tests/src/Functional/FillPdfSettingsFormTest.php b/tests/src/Functional/FillPdfSettingsFormTest.php
index 341d4c0ed6e13525f056d7b6a9cb83df0837b49d..8391ba0bdeeba36e7407d3a0738bc4d71c612aac 100644
--- a/tests/src/Functional/FillPdfSettingsFormTest.php
+++ b/tests/src/Functional/FillPdfSettingsFormTest.php
@@ -116,7 +116,7 @@ class FillPdfSettingsFormTest extends BrowserTestBase {
 
     // Verify that the site default scheme, which at this point is 'public', is
     // preselected but not yet saved in config.
-    $this->assertSession()->fieldValueEquals('template_scheme', file_default_scheme());
+    $this->assertSession()->fieldValueEquals('template_scheme', $this->config('system.file')->get('default_scheme'));
     $this->assertEqual($this->config('fillpdf.settings')->get('template_scheme'), 'private');
   }
 
diff --git a/tests/src/Traits/TestFillPdfTrait.php b/tests/src/Traits/TestFillPdfTrait.php
index 6dd64d96d76581c8d104370d427160947485a8fe..52fa369405fac7fd6488fcc3c559baefe909f66b 100644
--- a/tests/src/Traits/TestFillPdfTrait.php
+++ b/tests/src/Traits/TestFillPdfTrait.php
@@ -23,7 +23,7 @@ trait TestFillPdfTrait {
     // Merge in defaults.
     $configuration += [
       'allowed_schemes' => ['public', 'private'],
-      'template_scheme' => file_default_scheme(),
+      'template_scheme' => $this->config('system.file')->get('default_scheme'),
       'backend' => 'test',
     ];