diff --git a/CHANGELOG.md b/CHANGELOG.md
index 59b8105..21d2ef4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,7 +9,7 @@ and this project adheres to
 ## [Unreleased]
 ### Added
 - AST for the GraphQL schema.
-- Parser for the SchemaDefinition
+- Parser for the SchemaDefinition and TypeDefinition.
 - `Trans.argument`.
 
 ### Changed
diff --git a/src/Language/GraphQL/AST/Document.hs b/src/Language/GraphQL/AST/Document.hs
index 74c6ce2..9b156b2 100644
--- a/src/Language/GraphQL/AST/Document.hs
+++ b/src/Language/GraphQL/AST/Document.hs
@@ -12,6 +12,7 @@ module Language.GraphQL.AST.Document
     , Description(..)
     , Directive(..)
     , Document
+    , EnumValueDefinition(..)
     , ExecutableDefinition(..)
     , FieldDefinition(..)
     , FragmentDefinition(..)
@@ -289,7 +290,7 @@ data TypeDefinition
     | UnionTypeDefinition Description Name [Directive] (UnionMemberTypes [])
     | EnumTypeDefinition Description Name [Directive] [EnumValueDefinition]
     | InputObjectTypeDefinition
-        Description Name [Directive] InputFieldsDefinitionOpt
+        Description Name [Directive] [InputValueDefinition]
     deriving (Eq, Show)
 
 data TypeExtension
@@ -310,7 +311,7 @@ data TypeExtension
         Name [Directive] (NonEmpty EnumValueDefinition)
     | EnumTypeDirectivesExtension Name (NonEmpty Directive)
     | InputObjectTypeInputFieldsDefinitionExtension
-        Name [Directive] InputFieldsDefinition
+        Name [Directive] (NonEmpty InputValueDefinition)
     | InputObjectTypeDirectivesExtension Name (NonEmpty Directive)
     deriving (Eq, Show)
 
@@ -362,13 +363,3 @@ instance Foldable t => Show (UnionMemberTypes t) where
 
 data EnumValueDefinition = EnumValueDefinition Description Name [Directive]
     deriving (Eq, Show)
-
--- ** Input Objects
-
-newtype InputFieldsDefinition
-    = InputFieldsDefinition (NonEmpty InputValueDefinition)
-    deriving (Eq, Show)
-
-newtype InputFieldsDefinitionOpt
-    = InputFieldsDefinitionOpt [InputValueDefinition]
-    deriving (Eq, Show)
diff --git a/src/Language/GraphQL/AST/Parser.hs b/src/Language/GraphQL/AST/Parser.hs
index 41748b2..bb8a273 100644
--- a/src/Language/GraphQL/AST/Parser.hs
+++ b/src/Language/GraphQL/AST/Parser.hs
@@ -7,8 +7,8 @@ module Language.GraphQL.AST.Parser
     ) where
 
 import Control.Applicative (Alternative(..), optional)
+import Control.Applicative.Combinators (sepBy1)
 import qualified Control.Applicative.Combinators.NonEmpty as NonEmpty
-import Control.Applicative.Combinators (sepBy, sepBy1)
 import Data.Text (Text)
 import Language.GraphQL.AST.Document
 import Language.GraphQL.AST.Lexer
@@ -40,6 +40,8 @@ typeDefinition = scalarTypeDefinition
     <|> objectTypeDefinition
     <|> interfaceTypeDefinition
     <|> unionTypeDefinition
+    <|> enumTypeDefinition
+    <|> inputObjectTypeDefinition
     <?> "TypeDefinition"
 
 scalarTypeDefinition :: Parser TypeDefinition
@@ -93,6 +95,35 @@ interfaceTypeDefinition = InterfaceTypeDefinition
     <*> braces (many fieldDefinition)
     <?> "InterfaceTypeDefinition"
 
+enumTypeDefinition :: Parser TypeDefinition
+enumTypeDefinition = EnumTypeDefinition
+    <$> description
+    <* symbol "enum"
+    <*> name
+    <*> opt directives
+    <*> opt enumValuesDefinition
+    <?> "EnumTypeDefinition"
+  where
+    enumValuesDefinition = braces (some enumValueDefinition)
+
+inputObjectTypeDefinition :: Parser TypeDefinition
+inputObjectTypeDefinition = InputObjectTypeDefinition
+    <$> description
+    <* symbol "input"
+    <*> name
+    <*> opt directives
+    <*> opt inputFieldsDefinition
+    <?> "InputObjectTypeDefinition"
+  where
+    inputFieldsDefinition = braces (some inputValueDefinition)
+
+enumValueDefinition :: Parser EnumValueDefinition
+enumValueDefinition = EnumValueDefinition
+    <$> description
+    <*> enumValue
+    <*> opt directives
+    <?> "EnumValueDefinition"
+
 implementsInterfaces ::
     Foldable t =>
     (Parser Text -> Parser Text -> Parser (t NamedType)) ->
@@ -134,9 +165,8 @@ schemaDefinition = SchemaDefinition
     <*> opt directives
     <*> operationTypeDefinitions
     <?> "SchemaDefinition"
-
-operationTypeDefinitions :: Parser OperationTypeDefinitions
-operationTypeDefinitions  = braces $ manyNE operationTypeDefinition
+  where
+    operationTypeDefinitions  = braces $ NonEmpty.some operationTypeDefinition
 
 operationTypeDefinition :: Parser OperationTypeDefinition
 operationTypeDefinition = OperationTypeDefinition
@@ -244,15 +274,15 @@ value = Variable <$> variable
     booleanValue = True  <$ symbol "true"
                <|> False <$ symbol "false"
 
-    enumValue :: Parser Name
-    enumValue = but (symbol "true") *> but (symbol "false") *> but (symbol "null") *> name
-
     listValue :: Parser [Value]
     listValue = brackets $ some value
 
     objectValue :: Parser [ObjectField]
     objectValue = braces $ some objectField
 
+enumValue :: Parser Name
+enumValue = but (symbol "true") *> but (symbol "false") *> but (symbol "null") *> name
+
 objectField :: Parser ObjectField
 objectField = ObjectField <$> name <* colon <*> value
 
diff --git a/tests/Language/GraphQL/AST/ParserSpec.hs b/tests/Language/GraphQL/AST/ParserSpec.hs
index efb5b63..e561863 100644
--- a/tests/Language/GraphQL/AST/ParserSpec.hs
+++ b/tests/Language/GraphQL/AST/ParserSpec.hs
@@ -81,3 +81,31 @@ spec = describe "Parser" $ do
               name: String
             }
         |]
+
+    it "parses minimal enum type definition" $
+        parse document "" `shouldSucceedOn` [r|
+            enum Direction {
+              NORTH
+              EAST
+              SOUTH
+              WEST
+            }
+        |]
+
+    it "parses minimal enum type definition" $
+        parse document "" `shouldSucceedOn` [r|
+            enum Direction {
+              NORTH
+              EAST
+              SOUTH
+              WEST
+            }
+        |]
+
+    it "parses minimal input object type definition" $
+        parse document "" `shouldSucceedOn` [r|
+            input Point2D {
+              x: Float
+              y: Float
+            }
+        |]