diff --git a/core/lib/Drupal/Core/Config/Config.php b/core/lib/Drupal/Core/Config/Config.php
index b55d46b161..604b3b1ad7 100644
--- a/core/lib/Drupal/Core/Config/Config.php
+++ b/core/lib/Drupal/Core/Config/Config.php
@@ -85,7 +85,7 @@ public function get($key = '') {
     if (!isset($this->overriddenData)) {
       $this->setOverriddenData();
     }
-    return self::extractKeyedData($this->overriddenData, $key);
+    return NestedArray::getValue($this->overriddenData, $key ? explode('.', $key) : []);
   }
 
   /**
@@ -147,7 +147,7 @@ public function getOverrides($key = '') {
     if (empty($overrides)) {
       return NULL;
     }
-    return self::extractKeyedData($overrides, $key);
+    return NestedArray::getValue($overrides, $key ? explode('.', $key) : []);
   }
 
   /**
@@ -285,8 +285,7 @@ public function getOriginal($key = '', $apply_overrides = TRUE) {
       // Apply overrides.
       $original_data = $this->mergeOverridesWithData($original_data);
     }
-
-    return self::extractKeyedData($original_data, $key);
+    return NestedArray::getValue($original_data, $key ? explode('.', $key) : []);
   }
 
   /**
@@ -308,19 +307,4 @@ protected function mergeOverridesWithData(array $data) {
     return $data;
   }
 
-  /**
-   * Extract the value of a sub key in the data.
-   *
-   * @param array $data
-   *   The configuration data.
-   * @param string $key
-   *   A string that maps to a key within the configuration data.
-   *
-   * @return mixed
-   *   The data at the key or NULL if it is not set.
-   */
-  protected static function extractKeyedData(array $data, $key) {
-    return NestedArray::getValue($data, $key ? explode('.', $key) : []);
-  }
-
 }
diff --git a/core/lib/Drupal/Core/Config/ConfigBase.php b/core/lib/Drupal/Core/Config/ConfigBase.php
index 4f445ea21c..bb8149642a 100644
--- a/core/lib/Drupal/Core/Config/ConfigBase.php
+++ b/core/lib/Drupal/Core/Config/ConfigBase.php
@@ -129,19 +129,7 @@ public static function validateName($name) {
    *   The data that was requested.
    */
   public function get($key = '') {
-    if (empty($key)) {
-      return $this->data;
-    }
-    else {
-      $parts = explode('.', $key);
-      if (count($parts) == 1) {
-        return isset($this->data[$key]) ? $this->data[$key] : NULL;
-      }
-      else {
-        $value = NestedArray::getValue($this->data, $parts, $key_exists);
-        return $key_exists ? $value : NULL;
-      }
-    }
+    return NestedArray::getValue($this->data, $key ? explode('.', $key) : []);
   }
 
   /**