diff --git a/CHANGELOG.md b/CHANGELOG.md
index e6471cffc..897e0770d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## [0.4.5] - 2019-02-12
+
+### Fixed
+
+- Fixed the TypeScript definitions in `graphql-scalars.d.ts` (Credit: [@capaj](https://github.com/capaj))
+
 ## [0.4.4] - 2019-02-08
 
 ### Changed
diff --git a/graphql-scalars.d.ts b/graphql-scalars.d.ts
index 4f6dbff15..e1be30812 100644
--- a/graphql-scalars.d.ts
+++ b/graphql-scalars.d.ts
@@ -1,24 +1,49 @@
 import { GraphQLScalarType } from 'graphql';
 
+interface RegularExpressionOptions {
+  errorMessage: Function;
+}
+
 declare namespace GraphqlScalars {
-  declare const EmailAddress: GraphQLScalarType;
-  declare const DateTime: GraphQLScalarType;
-  declare const NonPositiveInt: GraphQLScalarType;
-  declare const PositiveInt: GraphQLScalarType;
-  declare const NonNegativeInt: GraphQLScalarType;
-  declare const NegativeInt: GraphQLScalarType;
-  declare const NonPositiveFloat: GraphQLScalarType;
-  declare const PositiveFloat: GraphQLScalarType;
-  declare const NonNegativeFloat: GraphQLScalarType;
-  declare const NegativeFloat: GraphQLScalarType;
-  declare const EmailAddress: GraphQLScalarType;
-  declare const URL: GraphQLScalarType;
-  declare const PhoneNumber: GraphQLScalarType;
-  declare const PostalCode: GraphQLScalarType;
+  const EmailAddress: GraphQLScalarType;
+  const DateTime: GraphQLScalarType;
+  const NonPositiveInt: GraphQLScalarType;
+  const PositiveInt: GraphQLScalarType;
+  const NonNegativeInt: GraphQLScalarType;
+  const NegativeInt: GraphQLScalarType;
+  const NonPositiveFloat: GraphQLScalarType;
+  const PositiveFloat: GraphQLScalarType;
+  const NonNegativeFloat: GraphQLScalarType;
+  const NegativeFloat: GraphQLScalarType;
+  const URL: GraphQLScalarType;
+  const PhoneNumber: GraphQLScalarType;
+  const PostalCode: GraphQLScalarType;
 
-  declare class RegularExpression extends GraphQLScalarType {
-    constructor(name: string, regex: RegExp);
+  class RegularExpression extends GraphQLScalarType {
+    constructor(
+      name: string,
+      regex: RegExp,
+      options?: RegularExpressionOptions,
+    );
   }
+
+  const DateTimeScalar: string;
+  const NonPositiveIntScalar: string;
+  const PositiveIntScalar: string;
+  const NonNegativeIntScalar: string;
+  const UnsignedIntScalar: string;
+  const NegativeIntScalar: string;
+  const NonPositiveFloatScalar: string;
+  const PositiveFloatScalar: string;
+  const NonNegativeFloatScalar: string;
+  const UnsignedFloatScalar: string;
+  const NegativeFloatScalar: string;
+  const EmailAddressScalar: string;
+  const URLScalar: string;
+  const PhoneNumberScalar: string;
+  const PostalCodeScalar: string;
+  const RegularExpressionScalar: string;
+  const OKGScalarDefinitions: string[];
 }
 
 export = GraphqlScalars;
diff --git a/package-lock.json b/package-lock.json
index 4510db9dd..22f3ed6b6 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "@okgrow/graphql-scalars",
-  "version": "0.4.4",
+  "version": "0.4.5",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
diff --git a/package.json b/package.json
index 7873eeb43..543188731 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@okgrow/graphql-scalars",
-  "version": "0.4.4",
+  "version": "0.4.5",
   "description": "A collection of scalar types not included in base GraphQL.",
   "repository": {
     "type": "git",