diff --git a/lib/internal/Magento/Framework/Phrase/Renderer/Placeholder.php b/lib/internal/Magento/Framework/Phrase/Renderer/Placeholder.php
index 140ab92dbc476..d6c0d133f6c58 100644
--- a/lib/internal/Magento/Framework/Phrase/Renderer/Placeholder.php
+++ b/lib/internal/Magento/Framework/Phrase/Renderer/Placeholder.php
@@ -23,16 +23,16 @@ public function render(array $source, array $arguments)
         $text = end($source);
 
         if ($arguments) {
-            $placeholders = array_map(
-                function ($key) {
-                    return '%' . (is_int($key) ? strval($key + 1) : $key);
-                },
-                array_keys($arguments)
-            );
+            $placeholders = array_map([$this, 'keyToPlaceholder'], array_keys($arguments));
             $pairs = array_combine($placeholders, $arguments);
             $text = strtr($text, $pairs);
         }
 
         return $text;
     }
+
+    private function keyToPlaceholder($key)
+    {
+        return '%' . (is_int($key) ? strval($key + 1) : $key);
+    }
 }