diff --git a/types/graphql/error/GraphQLError.d.ts b/types/graphql/error/GraphQLError.d.ts
index 12f65a506c..857f25b593 100644
--- a/types/graphql/error/GraphQLError.d.ts
+++ b/types/graphql/error/GraphQLError.d.ts
@@ -27,7 +27,7 @@ export class GraphQLError extends Error {
      *
      * Enumerable, and appears in the result of JSON.stringify().
      */
-    locations?: Array<{ line: number, column: number }> | void;
+    locations?: Array<{ line: number, column: number }> | undefined;
 
     /**
      * An array describing the JSON-path into the execution response which
@@ -35,23 +35,23 @@ export class GraphQLError extends Error {
      *
      * Enumerable, and appears in the result of JSON.stringify().
      */
-    path?: Array<string | number> | void;
+    path?: Array<string | number> | undefined;
 
     /**
      * An array of GraphQL AST Nodes corresponding to this error.
      */
-    nodes?: Array<ASTNode> | void;
+    nodes?: Array<ASTNode> | undefined;
 
     /**
      * The source GraphQL document corresponding to this error.
      */
-    source?: Source | void;
+    source?: Source | undefined;
 
     /**
      * An array of character offsets within the source GraphQL document
      * which correspond to this error.
      */
-    positions?: Array<number> | void;
+    positions?: Array<number> | undefined;
 
     /**
      * The original error thrown from a field resolver during execution.
diff --git a/types/graphql/index.d.ts b/types/graphql/index.d.ts
index 43d810de02..de2a1405e6 100644
--- a/types/graphql/index.d.ts
+++ b/types/graphql/index.d.ts
@@ -1,6 +1,6 @@
-// Type definitions for graphql v0.8.2
+// Type definitions for graphql 0.9
 // Project: https://www.npmjs.com/package/graphql
-// Definitions by: TonyYang <https://github.com/TonyPythoneer>, Caleb Meredith <https://github.com/calebmer>, Dominic Watson <https://github.com/intellix>
+// Definitions by: TonyYang <https://github.com/TonyPythoneer>, Caleb Meredith <https://github.com/calebmer>, Dominic Watson <https://github.com/intellix>, Firede <https://github.com/firede>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
 
@@ -105,6 +105,12 @@ export {
     // Asserts a string is a valid GraphQL name.
     assertValidName,
 
+    // Compares two GraphQLSchemas and detects breaking changes.
+    findBreakingChanges,
+
+    // Report all deprecated usage within a GraphQL document.
+    findDeprecatedUsages,
+
     BreakingChange,
 
     IntrospectionDirective,
diff --git a/types/graphql/language/ast.d.ts b/types/graphql/language/ast.d.ts
index 238cbe7210..d0f25b65d0 100644
--- a/types/graphql/language/ast.d.ts
+++ b/types/graphql/language/ast.d.ts
@@ -85,7 +85,7 @@ export type Token = {
     /**
      * For non-punctuation tokens, represents the interpreted value of the token.
      */
-    value: string | void;
+    value: string | undefined;
 
     /**
      * Tokens exist as nodes in a double-linked-list amongst all tokens
diff --git a/types/graphql/language/visitor.d.ts b/types/graphql/language/visitor.d.ts
index 1d0f399d6e..d4c528501e 100644
--- a/types/graphql/language/visitor.d.ts
+++ b/types/graphql/language/visitor.d.ts
@@ -42,7 +42,7 @@ export const QueryDocumentKeys: {
 
 export const BREAK: any;
 
-export function visit(root: any, visitor: any, keyMap: any): any;
+export function visit(root: any, visitor: any, keyMap?: any): any;
 
 export function visitInParallel(visitors: any): any;
 
diff --git a/types/graphql/type/definition.d.ts b/types/graphql/type/definition.d.ts
index 6fef914d8e..cf077ad5ba 100644
--- a/types/graphql/type/definition.d.ts
+++ b/types/graphql/type/definition.d.ts
@@ -126,6 +126,10 @@ export type GraphQLNamedType =
     GraphQLEnumType |
     GraphQLInputObjectType;
 
+export function isNamedType(type: GraphQLType): boolean;
+
+export function assertNamedType(type: GraphQLType): GraphQLNamedType;
+
 export function getNamedType(type: GraphQLType): GraphQLNamedType;
 
 /**
@@ -237,13 +241,13 @@ export type GraphQLTypeResolver<TSource, TContext> = (
     value: TSource,
     context: TContext,
     info: GraphQLResolveInfo
-) => GraphQLObjectType;
+) => GraphQLObjectType | string | Promise<GraphQLObjectType | string>;
 
 export type GraphQLIsTypeOfFn<TSource, TContext> = (
     source: TSource,
     context: TContext,
     info: GraphQLResolveInfo
-) => boolean;
+) => boolean | Promise<boolean>;
 
 export type GraphQLFieldResolver<TSource, TContext> = (
     source: TSource,
@@ -265,7 +269,7 @@ export interface GraphQLResolveInfo {
     variableValues: { [variableName: string]: any };
 }
 
-export type ResponsePath = { prev: ResponsePath, key: string | number } | void;
+export type ResponsePath = { prev: ResponsePath, key: string | number } | undefined;
 
 export interface GraphQLFieldConfig<TSource, TContext> {
     type: GraphQLOutputType;
@@ -426,6 +430,7 @@ export class GraphQLEnumType {
 
     constructor(config: GraphQLEnumTypeConfig);
     getValues(): Array<GraphQLEnumValue>;
+    getValue(name: string): GraphQLEnumValue;
     serialize(value: any): string;
     parseValue(value: any): any;
     parseLiteral(valueNode: ValueNode): any;
diff --git a/types/graphql/utilities/TypeInfo.d.ts b/types/graphql/utilities/TypeInfo.d.ts
index 2957114ae5..b4fa855569 100644
--- a/types/graphql/utilities/TypeInfo.d.ts
+++ b/types/graphql/utilities/TypeInfo.d.ts
@@ -5,6 +5,7 @@ import {
     GraphQLInputType,
     GraphQLField,
     GraphQLArgument,
+    GraphQLEnumValue,
     GraphQLType,
 } from '../type/definition';
 import { GraphQLDirective } from '../type/directives';
@@ -30,6 +31,7 @@ export class TypeInfo {
     getFieldDef(): GraphQLField<any, any>;
     getDirective(): GraphQLDirective;
     getArgument(): GraphQLArgument;
+    getEnumValue(): GraphQLEnumValue;
     enter(node: ASTNode): any;
     leave(node: ASTNode): any;
 }
@@ -40,4 +42,4 @@ export interface getFieldDef {
         parentType: GraphQLType,
         fieldNode: FieldNode
     ): GraphQLField<any, any>
-}
\ No newline at end of file
+}
diff --git a/types/graphql/utilities/buildASTSchema.d.ts b/types/graphql/utilities/buildASTSchema.d.ts
index cf782a30ec..94f4e2a47a 100644
--- a/types/graphql/utilities/buildASTSchema.d.ts
+++ b/types/graphql/utilities/buildASTSchema.d.ts
@@ -26,15 +26,3 @@ export function getDescription(node: { loc?: Location }): string;
  * document.
 */
 export function buildSchema(source: string | Source): GraphQLSchema;
-
-/**
- * Given an ast node, returns its string description based on a contiguous
- * block full-line of comments preceding it.
- */
-export function getDescription(node: { loc?: Location }): string;
-
-/**
- * A helper function to build a GraphQLSchema directly from a source
- * document.
- */
-export function buildSchema(source: string | Source): GraphQLSchema;
diff --git a/types/graphql/utilities/findDeprecatedUsages.d.ts b/types/graphql/utilities/findDeprecatedUsages.d.ts
new file mode 100644
index 0000000000..58e9ae1685
--- /dev/null
+++ b/types/graphql/utilities/findDeprecatedUsages.d.ts
@@ -0,0 +1,13 @@
+import { GraphQLSchema } from '../type/schema';
+import { DocumentNode } from '../language/ast';
+import { GraphQLError } from '../error/GraphQLError';
+
+/**
+ * A validation rule which reports deprecated usages.
+ *
+ * Returns a list of GraphQLError instances describing each deprecated use.
+ */
+export function findDeprecatedUsages(
+    schema: GraphQLSchema,
+    ast: DocumentNode
+): Array<GraphQLError>
diff --git a/types/graphql/utilities/getOperationAST.d.ts b/types/graphql/utilities/getOperationAST.d.ts
index 65c7735a5d..ce99d39b2b 100644
--- a/types/graphql/utilities/getOperationAST.d.ts
+++ b/types/graphql/utilities/getOperationAST.d.ts
@@ -7,5 +7,5 @@ import { DocumentNode, OperationDefinitionNode } from '../language/ast';
  */
 export function getOperationAST(
     documentAST: DocumentNode,
-    operationName: string
+    operationName?: string
 ): OperationDefinitionNode;
diff --git a/types/graphql/utilities/index.d.ts b/types/graphql/utilities/index.d.ts
index 47cfd70ff9..8815046735 100644
--- a/types/graphql/utilities/index.d.ts
+++ b/types/graphql/utilities/index.d.ts
@@ -73,3 +73,6 @@ export { assertValidName } from './assertValidName';
 // Compares two GraphQLSchemas and detects breaking changes.
 export { findBreakingChanges } from './findBreakingChanges';
 export { BreakingChange } from './findBreakingChanges';
+
+// Report all deprecated usage within a GraphQL document.
+export { findDeprecatedUsages } from './findDeprecatedUsages';