diff --git a/src/language/ast.js b/src/language/ast.js
index 8a1a527fd4..6325c25ef4 100644
--- a/src/language/ast.js
+++ b/src/language/ast.js
@@ -124,14 +124,14 @@ export type ASTNode =
   | EnumTypeDefinitionNode
   | EnumValueDefinitionNode
   | InputObjectTypeDefinitionNode
+  | DirectiveDefinitionNode
   | SchemaExtensionNode
   | ScalarTypeExtensionNode
   | ObjectTypeExtensionNode
   | InterfaceTypeExtensionNode
   | UnionTypeExtensionNode
   | EnumTypeExtensionNode
-  | InputObjectTypeExtensionNode
-  | DirectiveDefinitionNode;
+  | InputObjectTypeExtensionNode;
 
 /**
  * Utility type listing all nodes indexed by their kind.
@@ -172,6 +172,7 @@ export type ASTKindToNode = {
   EnumTypeDefinition: EnumTypeDefinitionNode,
   EnumValueDefinition: EnumValueDefinitionNode,
   InputObjectTypeDefinition: InputObjectTypeDefinitionNode,
+  DirectiveDefinition: DirectiveDefinitionNode,
   SchemaExtension: SchemaExtensionNode,
   ScalarTypeExtension: ScalarTypeExtensionNode,
   ObjectTypeExtension: ObjectTypeExtensionNode,
@@ -179,7 +180,6 @@ export type ASTKindToNode = {
   UnionTypeExtension: UnionTypeExtensionNode,
   EnumTypeExtension: EnumTypeExtensionNode,
   InputObjectTypeExtension: InputObjectTypeExtensionNode,
-  DirectiveDefinition: DirectiveDefinitionNode,
 };
 
 // Name
@@ -390,8 +390,8 @@ export type NonNullTypeNode = {
 export type TypeSystemDefinitionNode =
   | SchemaDefinitionNode
   | TypeDefinitionNode
-  | TypeSystemExtensionNode
-  | DirectiveDefinitionNode;
+  | DirectiveDefinitionNode
+  | TypeSystemExtensionNode;
 
 export type SchemaDefinitionNode = {
   +kind: 'SchemaDefinition',
diff --git a/src/language/kinds.js b/src/language/kinds.js
index 40f40b1ffa..c6f1587ee4 100644
--- a/src/language/kinds.js
+++ b/src/language/kinds.js
@@ -62,6 +62,9 @@ export const Kind = Object.freeze({
   ENUM_VALUE_DEFINITION: 'EnumValueDefinition',
   INPUT_OBJECT_TYPE_DEFINITION: 'InputObjectTypeDefinition',
 
+  // Directive Definitions
+  DIRECTIVE_DEFINITION: 'DirectiveDefinition',
+
   // Type System Extensions
   SCHEMA_EXTENSION: 'SchemaExtension',
 
@@ -72,9 +75,6 @@ export const Kind = Object.freeze({
   UNION_TYPE_EXTENSION: 'UnionTypeExtension',
   ENUM_TYPE_EXTENSION: 'EnumTypeExtension',
   INPUT_OBJECT_TYPE_EXTENSION: 'InputObjectTypeExtension',
-
-  // Directive Definitions
-  DIRECTIVE_DEFINITION: 'DirectiveDefinition',
 });
 
 /**
diff --git a/src/language/parser.js b/src/language/parser.js
index bc2c23b3bf..366233ca38 100644
--- a/src/language/parser.js
+++ b/src/language/parser.js
@@ -752,10 +752,10 @@ export function parseNamedType(lexer: Lexer<*>): NamedTypeNode {
 
 /**
  * TypeSystemDefinition :
- *   - TypeSystemExtension
  *   - SchemaDefinition
  *   - TypeDefinition
  *   - DirectiveDefinition
+ *   - TypeSystemExtension
  *
  * TypeDefinition :
  *   - ScalarTypeDefinition
@@ -785,10 +785,10 @@ function parseTypeSystemDefinition(lexer: Lexer<*>): TypeSystemDefinitionNode {
         return parseEnumTypeDefinition(lexer);
       case 'input':
         return parseInputObjectTypeDefinition(lexer);
-      case 'extend':
-        return parseTypeSystemExtension(lexer);
       case 'directive':
         return parseDirectiveDefinition(lexer);
+      case 'extend':
+        return parseTypeSystemExtension(lexer);
     }
   }