diff --git a/core/lib/Drupal/Core/Config/Config.php b/core/lib/Drupal/Core/Config/Config.php
index e6b3295b3e..ae3869a02c 100644
--- a/core/lib/Drupal/Core/Config/Config.php
+++ b/core/lib/Drupal/Core/Config/Config.php
@@ -85,19 +85,7 @@ public function get($key = '') {
     if (!isset($this->overriddenData)) {
       $this->setOverriddenData();
     }
-    if (empty($key)) {
-      return $this->overriddenData;
-    }
-    else {
-      $parts = explode('.', $key);
-      if (count($parts) == 1) {
-        return isset($this->overriddenData[$key]) ? $this->overriddenData[$key] : NULL;
-      }
-      else {
-        $value = NestedArray::getValue($this->overriddenData, $parts, $key_exists);
-        return $key_exists ? $value : NULL;
-      }
-    }
+    return self::extractKeyedData($this->overriddenData, $key);
   }
 
   /**
@@ -142,17 +130,24 @@ public function setModuleOverride(array $data) {
   }
 
   /**
-   * Returns whether overrides apply to this configuration or not.
+   * Returns overrides that apply to this configuration.
    *
    * Simply comparing the the data from getOriginal() with and without overrides
    * does not help to detect overrides if the override happens to have the same
    * value as the original data.
    *
-   * @return bool
-   *   True if overrides apply to this configuration, false otherwise.
+   * @param string $key
+   *   A string that maps to a key within the configuration data.
+   *
+   * @return mixed
+   *   The value of the override or NULL if not overwritten.
    */
-  public function hasOverrides() {
-    return !empty($this->moduleOverrides) || !empty($this->settingsOverrides);
+  public function getOverrides($key = '') {
+    $overrides = $this->mergeOverridesWithData([]);
+    if (empty($overrides)) {
+      return NULL;
+    }
+    return self::extractKeyedData($overrides, $key);
   }
 
   /**
@@ -167,13 +162,7 @@ public function hasOverrides() {
    *   The configuration object.
    */
   protected function setOverriddenData() {
-    $this->overriddenData = $this->data;
-    if (isset($this->moduleOverrides) && is_array($this->moduleOverrides)) {
-      $this->overriddenData = NestedArray::mergeDeepArray([$this->overriddenData, $this->moduleOverrides], TRUE);
-    }
-    if (isset($this->settingsOverrides) && is_array($this->settingsOverrides)) {
-      $this->overriddenData = NestedArray::mergeDeepArray([$this->overriddenData, $this->settingsOverrides], TRUE);
-    }
+    $this->overriddenData = $this->mergeOverridesWithData($this->data);
     return $this;
   }
 
@@ -294,27 +283,29 @@ public function getOriginal($key = '', $apply_overrides = TRUE) {
     $original_data = $this->originalData;
     if ($apply_overrides) {
       // Apply overrides.
-      if (isset($this->moduleOverrides) && is_array($this->moduleOverrides)) {
-        $original_data = NestedArray::mergeDeepArray([$original_data, $this->moduleOverrides], TRUE);
-      }
-      if (isset($this->settingsOverrides) && is_array($this->settingsOverrides)) {
-        $original_data = NestedArray::mergeDeepArray([$original_data, $this->settingsOverrides], TRUE);
-      }
+      $original_data = $this->mergeOverridesWithData($original_data);
     }
 
-    if (empty($key)) {
-      return $original_data;
+    return self::extractKeyedData($original_data, $key);
+  }
+
+  /**
+   * Merge module and settings overrides with the provided data.
+   *
+   * @param array $data
+   *   The data to merge the overrides with.
+   *
+   * @return array
+   *   The overwritten data, unchanged if no overrides apply.
+   */
+  protected function mergeOverridesWithData(array $data) {
+    if (isset($this->moduleOverrides) && is_array($this->moduleOverrides)) {
+      $data = NestedArray::mergeDeepArray([$data, $this->moduleOverrides], TRUE);
     }
-    else {
-      $parts = explode('.', $key);
-      if (count($parts) == 1) {
-        return isset($original_data[$key]) ? $original_data[$key] : NULL;
-      }
-      else {
-        $value = NestedArray::getValue($original_data, $parts, $key_exists);
-        return $key_exists ? $value : NULL;
-      }
+    if (isset($this->settingsOverrides) && is_array($this->settingsOverrides)) {
+      $data = NestedArray::mergeDeepArray([$data, $this->settingsOverrides], TRUE);
     }
+    return $data;
   }
 
 }
diff --git a/core/lib/Drupal/Core/Config/ConfigBase.php b/core/lib/Drupal/Core/Config/ConfigBase.php
index 4f445ea21c..64f348a9a7 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 ? $value : NULL;
-      }
-    }
+    return self::extractKeyedData($this->data, $key);
   }
 
   /**
@@ -295,4 +283,33 @@ protected function castSafeStrings($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.
+   *
+   * @see \Drupal\Core\Config\ConfigBase::get
+   */
+  protected static function extractKeyedData(array $data, $key) {
+    if (empty($key)) {
+      return $data;
+    }
+    else {
+      $parts = explode('.', $key);
+      if (count($parts) == 1) {
+        return isset($data[$key]) ? $data[$key] : NULL;
+      }
+      else {
+        $value = NestedArray::getValue($data, $parts, $key_exists);
+        return $key_exists ? $value : NULL;
+      }
+    }
+  }
+
 }
diff --git a/core/tests/Drupal/Tests/Core/Config/ConfigTest.php b/core/tests/Drupal/Tests/Core/Config/ConfigTest.php
index 746e620917..8633e59fed 100644
--- a/core/tests/Drupal/Tests/Core/Config/ConfigTest.php
+++ b/core/tests/Drupal/Tests/Core/Config/ConfigTest.php
@@ -173,6 +173,7 @@ public function testSaveExisting($data) {
    * @covers ::setModuleOverride
    * @covers ::setSettingsOverride
    * @covers ::getOriginal
+   * @covers ::getOverrides
    * @dataProvider overrideDataProvider
    */
   public function testOverrideData($data, $module_data, $setting_data) {
@@ -184,39 +185,37 @@ public function testOverrideData($data, $module_data, $setting_data) {
 
     // Save so that the original data is stored.
     $this->config->save();
-
-    // Before overrides are set the configuration should indicate that.
-    $this->assertFalse($this->config->hasOverrides());
+    $this->assertNull($this->config->getOverrides());
 
     // Set module override data and check value before and after save.
     $this->config->setModuleOverride($module_data);
     $this->assertConfigDataEquals($module_data);
-    $this->assertTrue($this->config->hasOverrides());
+    $this->assertEquals($module_data, $this->config->getOverrides());
     $this->config->save();
     $this->assertConfigDataEquals($module_data);
-    $this->assertTrue($this->config->hasOverrides());
+    $this->assertEquals($module_data, $this->config->getOverrides());
 
     // Reset the module overrides.
     $this->config->setModuleOverride([]);
-    $this->assertFalse($this->config->hasOverrides());
+    $this->assertNull($this->config->getOverrides());
 
     // Set setting override data and check value before and after save.
     $this->config->setSettingsOverride($setting_data);
     $this->assertConfigDataEquals($setting_data);
-    $this->assertTrue($this->config->hasOverrides());
+    $this->assertEquals($setting_data, $this->config->getOverrides());
     $this->config->save();
     $this->assertConfigDataEquals($setting_data);
-    $this->assertTrue($this->config->hasOverrides());
+    $this->assertEquals($setting_data, $this->config->getOverrides());
 
     // Set module overrides again to ensure override order is correct.
     $this->config->setModuleOverride($module_data);
 
     // Setting data should be overriding module data.
     $this->assertConfigDataEquals($setting_data);
-    $this->assertTrue($this->config->hasOverrides());
+    $this->assertEquals($setting_data, $this->config->getOverrides());
     $this->config->save();
     $this->assertConfigDataEquals($setting_data);
-    $this->assertTrue($this->config->hasOverrides());
+    $this->assertEquals($setting_data, $this->config->getOverrides());
 
     // Check original data has not changed.
     $this->assertOriginalConfigDataEquals($data, FALSE);
@@ -228,16 +227,17 @@ public function testOverrideData($data, $module_data, $setting_data) {
     foreach ($setting_data as $key => $value) {
       $config_value = $this->config->getOriginal($key);
       $this->assertEquals($value, $config_value);
+      $this->assertEquals($value, $this->config->getOverrides($key));
     }
 
     // Check that the overrides can be completely reset.
     $this->config->setModuleOverride([]);
     $this->config->setSettingsOverride([]);
     $this->assertConfigDataEquals($data);
-    $this->assertFalse($this->config->hasOverrides());
+    $this->assertNull($this->config->getOverrides());
     $this->config->save();
     $this->assertConfigDataEquals($data);
-    $this->assertFalse($this->config->hasOverrides());
+    $this->assertNull($this->config->getOverrides());
   }
 
   /**