diff --git a/core/lib/Drupal/Core/Config/FileStorage.php b/core/lib/Drupal/Core/Config/FileStorage.php
index ded8052..a08af4b 100644
--- a/core/lib/Drupal/Core/Config/FileStorage.php
+++ b/core/lib/Drupal/Core/Config/FileStorage.php
@@ -163,7 +163,8 @@ protected function getParser() {
    */
   public function encode($data) {
     // The level where you switch to inline YAML is set to PHP_INT_MAX to ensure
-    // this does not occur.
+    // this does not occur. Also set the exceptionOnInvalidType parameter to
+    // TRUE, so exceptions are thrown for an invalid data type.
     return $this->getDumper()->dump($data, PHP_INT_MAX, 0, TRUE);
   }
 
diff --git a/core/modules/config/lib/Drupal/config/Tests/ConfigCRUDTest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigCRUDTest.php
index d0fb753..fec4aee 100644
--- a/core/modules/config/lib/Drupal/config/Tests/ConfigCRUDTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigCRUDTest.php
@@ -204,6 +204,7 @@ function testDataTypes() {
       'int' => 99,
       'octal' => 0775,
       'string' => 'string',
+      'string_int' => '1',
     );
     $this->assertIdentical($config->get(), $data);
 
@@ -219,21 +220,14 @@ function testDataTypes() {
     $config->setData($data)->save();
     $this->assertIdentical($config->get(), $data);
 
-    $data = array(
-      // Yaml cannot dump resources.
-      'stream' => fopen(__FILE__, 'r'),
-    );
-    foreach ($data as $key => $value) {
-      $config->set($key, $value);
-      try {
-        $config->save();
-        $this->fail('No Exception thrown upon saving invalid data type.');
-      }
-      catch (\Exception $e) {
-        $this->pass(format_string('%class thrown upon saving invalid data type.', array(
-          '%class' => get_class($e),
-        )));
-      }
+    try {
+      $config->set('stream', fopen(__FILE__, 'r'))->save();
+      $this->fail('No Exception thrown upon saving invalid data type.');
+    }
+    catch (\Exception $e) {
+      $this->pass(format_string('%class thrown upon saving invalid data type.', array(
+        '%class' => get_class($e),
+      )));
     }
   }
 
diff --git a/core/modules/config/tests/config_test/config/config_test.types.yml b/core/modules/config/tests/config_test/config/config_test.types.yml
index 36dc08d..664325f 100644
--- a/core/modules/config/tests/config_test/config/config_test.types.yml
+++ b/core/modules/config/tests/config_test/config/config_test.types.yml
@@ -5,4 +5,5 @@ float: 3.14159
 hex: 0xC
 int: 99
 octal: 0775
-string: string
\ No newline at end of file
+string: string
+string_int: '1'
\ No newline at end of file