diff --git a/proj4/index.d.ts b/proj4/index.d.ts
index d59063f51b..ff2b8334de 100644
--- a/proj4/index.d.ts
+++ b/proj4/index.d.ts
@@ -1,102 +1,67 @@
-// Type definitions for proj4 2.3.15
+// Type definitions for proj4 2.3
 // Project: https://github.com/proj4js/proj4js
 // Definitions by: Denis Carriere <https://github.com/DenisCarriere>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
-declare module "proj4" {
-    const TemplateCoordinates: Array<number> | InterfaceCoordinates;
+declare namespace proj4 {
+    type TemplateCoordinates = number[] | InterfaceCoordinates;
 
     interface InterfaceCoordinates {
-        x: number,
-        y: number,
-        z?: number,
-        m?: number
+        x: number;
+        y: number;
+        z?: number;
+        m?: number;
     }
 
     interface InterfaceDatum {
-        datum_type: number
-        a: number
-        b: number
-        es: number
-        ep2: number
+        datum_type: number;
+        a: number;
+        b: number;
+        es: number;
+        ep2: number;
     }
 
-    interface Proj4Static {
-        forward(coordinates: typeof TemplateCoordinates): Array<number>
-        inverse(coordinates: typeof TemplateCoordinates): Array<number>
+    interface Static {
+        forward(coordinates: TemplateCoordinates): number[];
+        inverse(coordinates: TemplateCoordinates): number[];
     }
 
     interface InterfaceProjection {
-        datum: string
-        b: number
-        rf: number
-        sphere: number
-        es: number
-        e: number
-        ep2: number
-        forward(coordinates: typeof TemplateCoordinates): Array<number>
-        inverse(coordinates: typeof TemplateCoordinates): Array<number>
+        datum: string;
+        b: number;
+        rf: number;
+        sphere: number;
+        es: number;
+        e: number;
+        ep2: number;
+        forward(coordinates: TemplateCoordinates): number[];
+        inverse(coordinates: TemplateCoordinates): number[];
     }
 
-    namespace proj4 {
-        /**
-         * @name defaultDatum
-         */
-        export const defaultDatum: string;
+    export const defaultDatum: string;
 
-        /**
-         * @name Proj
-         */
-        export function Proj(srsCode:any, callback?: any): InterfaceProjection;
-        
-        /**
-         * @name WGS84
-         */
-        export const WGS84: any;
+    export function Proj(srsCode: any, callback?: any): InterfaceProjection;
 
-        /**
-         * Depecrated v3
-         * @name Point
-         */
-        export function Point(x: number, y: number, z?: number): InterfaceCoordinates;
-        export function Point(coordinates: Array<number>): InterfaceCoordinates;
-        export function Point(coordinates: InterfaceCoordinates): InterfaceCoordinates;
-        export function Point(coordinates: string): InterfaceCoordinates;
-        
-        /**
-         * @name toPoint
-         */
-        export function toPoint(array: Array<number>): InterfaceCoordinates;
-        
-        /**
-         * @name defs
-         */
-        export function defs(name: string): any;
-        export function defs(name: string, projection: string): any;
-        export function defs(name: Array<Array<string>>): any;
-
-        /**
-         * @name transform
-         */
-        export function transform(source: InterfaceProjection, dest: InterfaceProjection, point: typeof TemplateCoordinates): any;
-
-        /**
-         * @name mgrs
-         */
-        export function mgrs(coordinates: Array<number>, accuracy: number): string;
-
-        /**
-         * @name version
-         */
-        export const version: string;
-    }
+    export const WGS84: any;
 
     /**
-     * @name proj4
+     * Depecrated v3
      */
-    function proj4(fromProjection: string): Proj4Static;
-    function proj4(fromProjection: string, toProjection: string): Proj4Static;
-    function proj4(fromProjection: string, coordinates: typeof TemplateCoordinates): Array<number>;
-    function proj4(fromProjection: string, toProjection: string, coordinates: typeof TemplateCoordinates): Array<number>;
-    export = proj4
+    export function Point(x: number, y: number, z?: number): InterfaceCoordinates;
+    export function Point(coordinates: TemplateCoordinates | string): InterfaceCoordinates;
+
+    export function toPoint(array: number[]): InterfaceCoordinates;
+
+    export function defs(name: string, projection?: string): any;
+    export function defs(name: string[][]): any;
+
+    export function transform(source: InterfaceProjection, dest: InterfaceProjection, point: TemplateCoordinates): any;
+
+    export function mgrs(coordinates: number[], accuracy: number): string;
+
+    export const version: string;
 }
+
+declare function proj4(fromProjection: string, toProjection?: string, coordinates?: proj4.TemplateCoordinates): proj4.Static;
+declare function proj4(fromProjection: string, coordinates: proj4.TemplateCoordinates): number[];
+export = proj4;
diff --git a/proj4/proj4-tests.ts b/proj4/proj4-tests.ts
index 72fa804c6e..2c658b8f24 100644
--- a/proj4/proj4-tests.ts
+++ b/proj4/proj4-tests.ts
@@ -1,49 +1,49 @@
-import * as proj4 from 'proj4'
+import * as proj4 from 'proj4';
 
 ///////////////////////////////////////////
 // Tests data initialisation
 ///////////////////////////////////////////
-const name = 'WGS84'
+const name = 'WGS84';
 const epsg = {
     4269: '+title=NAD83 (long/lat) +proj=longlat +a=6378137.0 +b=6356752.31414036 +ellps=GRS80 +datum=NAD83 +units=degrees',
     4326: '+title=WGS 84 (long/lat) +proj=longlat +ellps=WGS84 +datum=WGS84 +units=degrees',
-}
-const point1 = [-71, 41]
-const point2 = {x: 2, y: 5}
-const mgrs = "24XWT783908"
+};
+const point1 = [-71, 41];
+const point2 = {x: 2, y: 5};
+const mgrs = "24XWT783908";
 
 ///////////////////////////////////////////
 // Tests Measurement
 ///////////////////////////////////////////
-proj4(epsg['4269'], epsg['4326'], point1)
-proj4(epsg['4269'], point1)
-proj4(epsg['4269'], epsg['4326']).forward(point2)
-proj4(epsg['4269'], epsg['4326']).inverse(point2)
+proj4(epsg['4269'], epsg['4326'], point1);
+proj4(epsg['4269'], point1);
+proj4(epsg['4269'], epsg['4326']).forward(point2);
+proj4(epsg['4269'], epsg['4326']).inverse(point2);
 
 ///////////////////////////////////
 // Named Projections
 ///////////////////////////////////
-proj4.defs('WGS84', epsg['4326'])
+proj4.defs('WGS84', epsg['4326']);
 proj4.defs([
   ['EPSG:4326', epsg['4326']],
   ['EPSG:4269', epsg['4269']]
-])
-proj4.defs('urn:x-ogc:def:crs:EPSG:4326', proj4.defs('EPSG:4326'))
+]);
+proj4.defs('urn:x-ogc:def:crs:EPSG:4326', proj4.defs('EPSG:4326'));
 
 ///////////////////////////////////
 // Utils
 ///////////////////////////////////
 // WGS84
-proj4.WGS84
+proj4.WGS84;
 
 // Proj
-proj4.Proj('WGS84')
+proj4.Proj('WGS84');
 
 // toPoint
-proj4.toPoint([1, 2])
-proj4.toPoint([1, 2, 3])
-proj4.toPoint([1, 2, 3, 4])
+proj4.toPoint([1, 2]);
+proj4.toPoint([1, 2, 3]);
+proj4.toPoint([1, 2, 3, 4]);
 
 // Point
 // WARNING: Deprecated in v3
-proj4.Point([1, 2, 3, 4])
\ No newline at end of file
+proj4.Point([1, 2, 3, 4]);
\ No newline at end of file
diff --git a/proj4/tslint.json b/proj4/tslint.json
new file mode 100644
index 0000000000..2221e40e4a
--- /dev/null
+++ b/proj4/tslint.json
@@ -0,0 +1 @@
+{ "extends": "../tslint.json" }
\ No newline at end of file