diff --git a/types/jquery.nicescroll/index.d.ts b/types/jquery.nicescroll/index.d.ts
index 1b5b714cb8..8228ae5209 100644
--- a/types/jquery.nicescroll/index.d.ts
+++ b/types/jquery.nicescroll/index.d.ts
@@ -1,4 +1,4 @@
-// Type definitions for jquery.nicescroll 3.7.6
+// Type definitions for jquery.nicescroll 3.7
 // Project: https://nicescroll.areaaperta.com
 // Definitions by: Bohdan Stupak <https://github.com/Wkalmar>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
@@ -8,98 +8,98 @@
 
 declare namespace JQueryNiceScroll {
     interface NiceScrollPage {
-        maxw: number
-        maxh: number
-        width: number
-        height: number
-        w: number
-        h: number
+        maxw: number;
+        maxh: number;
+        width: number;
+        height: number;
+        w: number;
+        h: number;
     }
-    
+
     interface NiceScroll {
-        show(): NiceScroll
-        hide(): NiceScroll
-        toggle(): NiceScroll
-        onResize(e?: Event, page?: NiceScrollPage): NiceScroll
-        resize(e?: Event, page?: NiceScrollPage): NiceScroll
-        remove(): void
-        stop(): NiceScroll
-        doScrollPos(x: number, y: number, spd: number): void
-        doScrollLeft(x: number, duration: number): void
-        doScrollTop(x: number, duration: number): void
+        show(): NiceScroll;
+        hide(): NiceScroll;
+        toggle(): NiceScroll;
+        onResize(e?: Event, page?: NiceScrollPage): NiceScroll;
+        resize(e?: Event, page?: NiceScrollPage): NiceScroll;
+        remove(): void;
+        stop(): NiceScroll;
+        doScrollPos(x: number, y: number, spd: number): void;
+        doScrollLeft(x: number, duration: number): void;
+        doScrollTop(x: number, duration: number): void;
     }
-    
+
     interface NiceScrollOptions {
-        zindex?: "auto" | number
-        cursoropacitymin?: number
-        cursoropacitymax?: number
-        cursorcolor?: string
-        cursorwidth?: string
-        cursorborder?: string
-        cursorborderradius?: string
-        scrollspeed?: number
-        mousescrollstep?: number
-        touchbehavior?: boolean
-        emulatetouch?: boolean
-        hwacceleration?: boolean
-        usetransition?: boolean
-        boxzoom?: boolean
-        dblclickzoom?: boolean
-        gesturezoom?: boolean
-        grabcursorenabled?: boolean
-        autohidemode?: "leave" | "scroll" | "cursor" | "hidden" | boolean
-        background?: string
-        iframeautoresize?: boolean
-        cursorminheight?: number
-        preservenativescrolling?: boolean
+        zindex?: "auto" | number;
+        cursoropacitymin?: number;
+        cursoropacitymax?: number;
+        cursorcolor?: string;
+        cursorwidth?: string;
+        cursorborder?: string;
+        cursorborderradius?: string;
+        scrollspeed?: number;
+        mousescrollstep?: number;
+        touchbehavior?: boolean;
+        emulatetouch?: boolean;
+        hwacceleration?: boolean;
+        usetransition?: boolean;
+        boxzoom?: boolean;
+        dblclickzoom?: boolean;
+        gesturezoom?: boolean;
+        grabcursorenabled?: boolean;
+        autohidemode?: "leave" | "scroll" | "cursor" | "hidden" | boolean;
+        background?: string;
+        iframeautoresize?: boolean;
+        cursorminheight?: number;
+        preservenativescrolling?: boolean;
         railoffset?: boolean | {
-            top?: number
-            left?: number
-        }
+            top?: number;
+            left?: number;
+        };
         railhoffset?: boolean  | {
-            top?: number
-            left?: number
-        }
-        bouncescroll?: boolean
-        spacebarenabled?: boolean
+            top?: number;
+            left?: number;
+        };
+        bouncescroll?: boolean;
+        spacebarenabled?: boolean;
         railpadding?: {
-          top: number
-          right: number
-          left: number
-          bottom: number
-        }
-        disableoutline?: boolean
-        horizrailenabled?: boolean
-        railalign?: "right" | "left" | "top" | "bottom"
-        railvalign?: "right" | "left" | "top" | "bottom"
-        enabletranslate3d?: boolean
-        enablemousewheel?: boolean
-        enablekeyboard?: boolean
-        smoothscroll?: boolean
-        sensitiverail?: boolean
-        enablemouselockapi?: boolean
-        cursorfixedheight?: number
-        directionlockdeadzone?: number
-        hidecursordelay?: number
-        nativeparentscrolling?: boolean
-        enablescrollonselection?: boolean
-        overflowx?: "auto" | "hidden" | "inherit" | "initial" | "overlay" | "scroll" | "unset" | "visible"
-        overflowy?: "auto" | "hidden" | "inherit" | "initial" | "overlay" | "scroll" | "unset" | "visible"
-        cursordragspeed?: number
-        rtlmode?: "auto" | boolean
-        cursordragontouch?: boolean
-        oneaxismousemode?: "auto" | boolean
-        scriptpath?: string
-        preventmultitouchscrolling?: boolean
-        disablemutationobserver?: boolean
-        enableobserver?: boolean
-        scrollbarid?: string
-        scrollCLass?: string
-    }  
+          top: number;
+          right: number;
+          left: number;
+          bottom: number;
+        };
+        disableoutline?: boolean;
+        horizrailenabled?: boolean;
+        railalign?: "right" | "left" | "top" | "bottom";
+        railvalign?: "right" | "left" | "top" | "bottom";
+        enabletranslate3d?: boolean;
+        enablemousewheel?: boolean;
+        enablekeyboard?: boolean;
+        smoothscroll?: boolean;
+        sensitiverail?: boolean;
+        enablemouselockapi?: boolean;
+        cursorfixedheight?: number;
+        directionlockdeadzone?: number;
+        hidecursordelay?: number;
+        nativeparentscrolling?: boolean;
+        enablescrollonselection?: boolean;
+        overflowx?: "auto" | "hidden" | "inherit" | "initial" | "overlay" | "scroll" | "unset" | "visible";
+        overflowy?: "auto" | "hidden" | "inherit" | "initial" | "overlay" | "scroll" | "unset" | "visible";
+        cursordragspeed?: number;
+        rtlmode?: "auto" | boolean;
+        cursordragontouch?: boolean;
+        oneaxismousemode?: "auto" | boolean;
+        scriptpath?: string;
+        preventmultitouchscrolling?: boolean;
+        disablemutationobserver?: boolean;
+        enableobserver?: boolean;
+        scrollbarid?: string;
+        scrollCLass?: string;
+    }
 }
 
 interface JQuery {
-    niceScroll(options?: JQueryNiceScroll.NiceScrollOptions) : JQueryNiceScroll.NiceScroll;
-    niceScroll(wrapper: string, options: JQueryNiceScroll.NiceScrollOptions) : JQueryNiceScroll.NiceScroll;
-    getNiceScroll(index?: number) : JQueryNiceScroll.NiceScroll;
-}
\ No newline at end of file
+    niceScroll(options?: JQueryNiceScroll.NiceScrollOptions): JQueryNiceScroll.NiceScroll;
+    niceScroll(wrapper: string, options: JQueryNiceScroll.NiceScrollOptions): JQueryNiceScroll.NiceScroll;
+    getNiceScroll(index?: number): JQueryNiceScroll.NiceScroll;
+}
diff --git a/types/jquery.nicescroll/jquery.nicescroll-tests.ts b/types/jquery.nicescroll/jquery.nicescroll-tests.ts
index 2d4599d8d6..f4362530f9 100644
--- a/types/jquery.nicescroll/jquery.nicescroll-tests.ts
+++ b/types/jquery.nicescroll/jquery.nicescroll-tests.ts
@@ -1,23 +1,23 @@
-//cases from documentation
+// cases from documentation
 // 1. Simple mode, it styles document scrollbar:
-$(function() {  
+$(() => {
     $("body").niceScroll();
 });
 
 // 2. Instance with object returned:
 let nice;
-$(function() {  
+$(() => {
     nice = $("body").niceScroll();
 });
 
 // 3. Style a DIV and change cursor color:
-$(function() {  
-    $("#thisdiv").niceScroll({cursorcolor:"#00F"});
+$(() => {
+    $("#thisdiv").niceScroll({cursorcolor: "#00F"});
 });
 
 // 4. DIV with "wrapper", formed by two divs, the first is the vieport, the latter is the content:
-$(function() {
-    $("#viewportdiv").niceScroll("#wrapperdiv",{cursorcolor:"#00F"});
+$(() => {
+    $("#viewportdiv").niceScroll("#wrapperdiv", {cursorcolor: "#00F"});
 });
 
 // 5. Get nicescroll object:
@@ -33,9 +33,9 @@ $("#mydiv").getNiceScroll().resize();
 $("#mydiv").getNiceScroll(0).doScrollLeft(1, 2); // Scroll X Axis
 $("#mydiv").getNiceScroll(0).doScrollTop(1, 14); // Scroll Y Axis
 
-//other cases
+// other cases
 $(".ui-grid-viewport").niceScroll({
     cursorcolor: "#fff",
     cursorwidth: "8px",
     autohidemode: "leave"
-});
\ No newline at end of file
+});
diff --git a/types/jquery.nicescroll/tsconfig.json b/types/jquery.nicescroll/tsconfig.json
index a5d8cb44a3..9d94444fc2 100644
--- a/types/jquery.nicescroll/tsconfig.json
+++ b/types/jquery.nicescroll/tsconfig.json
@@ -7,7 +7,7 @@
         ],
         "noImplicitAny": true,
         "noImplicitThis": true,
-        "strictNullChecks": false,
+        "strictNullChecks": true,
         "strictFunctionTypes": true,
         "baseUrl": "../",
         "typeRoots": [
diff --git a/types/jquery.nicescroll/tslint.json b/types/jquery.nicescroll/tslint.json
index 8bc7a53d89..e60c15844f 100644
--- a/types/jquery.nicescroll/tslint.json
+++ b/types/jquery.nicescroll/tslint.json
@@ -1,3 +1,3 @@
 {
-    "extends": "dtslint/dt.json",    
-}
+    "extends": "dtslint/dt.json"
+}
\ No newline at end of file