diff --git a/src/Plugin/GraphQL/Schema/SdlSchemaPluginBase.php b/src/Plugin/GraphQL/Schema/SdlSchemaPluginBase.php
index 47d1e7f2c..905579916 100644
--- a/src/Plugin/GraphQL/Schema/SdlSchemaPluginBase.php
+++ b/src/Plugin/GraphQL/Schema/SdlSchemaPluginBase.php
@@ -174,9 +174,12 @@ protected function getSchemaDocument(array $extensions = []) {
     });
 
     $schema = array_merge([$this->getSchemaDefinition()], $extensions);
-    $ast = Parser::parse(implode("\n\n", $schema));
+    $schema = implode("\n\n", $schema);
+    // Parsing only to check syntax errors in the current schema.
+    $ast = Parser::parse($schema);
     if (empty($this->inDevelopment)) {
-      $this->astCache->set($cid, $ast, CacheBackendInterface::CACHE_PERMANENT, ['graphql']);
+      // Caching schema string.
+      $this->astCache->set($cid, $schema, CacheBackendInterface::CACHE_PERMANENT, ['graphql']);
     }
 
     return $ast;