src/Normalizer/ConfigEntityNormalizer.php | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/Normalizer/ConfigEntityNormalizer.php b/src/Normalizer/ConfigEntityNormalizer.php
index 1508ccb..36d82aa 100644
--- a/src/Normalizer/ConfigEntityNormalizer.php
+++ b/src/Normalizer/ConfigEntityNormalizer.php
@@ -95,8 +95,11 @@ class ConfigEntityNormalizer extends EntityNormalizer {
    * {@inheritdoc}
    */
   protected function prepareInput(array $data, ResourceType $resource_type, $format, array $context) {
-    // Config entities' data don't have properties needing denormalization.
-    return $data;
+    $prepared = [];
+    foreach ($data as $key => $value) {
+      $prepared[$resource_type->getInternalName($key)] = $value;
+    }
+    return $prepared;
   }
 
 }