diff --git a/core/lib/Drupal/Core/Template/SafeMarkup.php b/core/lib/Drupal/Core/Template/SafeMarkup.php
index d2c538a..5407dc3 100644
--- a/core/lib/Drupal/Core/Template/SafeMarkup.php
+++ b/core/lib/Drupal/Core/Template/SafeMarkup.php
@@ -47,6 +47,12 @@ public static function implode($delimiter, array $array) {
     return SafeMarkup::create(implode($delimiter, $array));
   }
 
+  public static function strReplace($search, $replace, $subject, &$count = NULL) {
+    $safe = $subject instanceof SafeMarkup;
+    $replacement = str_replace($search, $replace, $subject, $count);
+    return $safe ? SafeMarkup::create($replacement) : $replacement;
+  }
+
   /**
    * Renders the markup.
    *
diff --git a/core/modules/field/src/Plugin/views/field/Field.php b/core/modules/field/src/Plugin/views/field/Field.php
index a01cb34..4a949f5 100644
--- a/core/modules/field/src/Plugin/views/field/Field.php
+++ b/core/modules/field/src/Plugin/views/field/Field.php
@@ -691,7 +691,7 @@ protected function renderItems($items) {
       }
 
       if ($this->options['multi_type'] == 'separator') {
-        return SafeMarkup::implode(Xss::filterAdmin($this->options['separator']), $items);
+        return SafeMarkup::create(implode(Xss::filterAdmin($this->options['separator']), $items));
       }
       else {
         $item_list = array(
diff --git a/core/modules/node/src/NodeViewBuilder.php b/core/modules/node/src/NodeViewBuilder.php
index b210cae..138e1bd 100644
--- a/core/modules/node/src/NodeViewBuilder.php
+++ b/core/modules/node/src/NodeViewBuilder.php
@@ -125,7 +125,7 @@ public static function renderLinks(array $element, array $context) {
       \Drupal::moduleHandler()->alter('node_links', $links, $entity, $hook_context);
     }
     $markup = drupal_render($links);
-    $element['#markup'] = str_replace($placeholder, $markup, $element['#markup']);
+    $element['#markup'] = SafeMarkup::strReplace($placeholder, $markup, $element['#markup']);
 
     return $element;
   }
diff --git a/core/modules/views/views.module b/core/modules/views/views.module
index cc6e3d4..5a93d2e 100644
--- a/core/modules/views/views.module
+++ b/core/modules/views/views.module
@@ -904,7 +904,7 @@ function views_pre_render_views_form_views_form($element) {
   }
 
   // Apply substitutions to the rendered output.
-  $element['output']['#markup'] = str_replace($search, $replace, $element['output']['#markup']);
+  $element['output']['#markup'] = SafeMarkup::strReplace($search, $replace, $element['output']['#markup']);
 
   // Sort, render and add remaining form fields.
   $children = Element::children($element, TRUE);