diff --git a/types/once/index.d.ts b/types/once/index.d.ts
index 325edfab81..4561e28316 100644
--- a/types/once/index.d.ts
+++ b/types/once/index.d.ts
@@ -1,23 +1,48 @@
-// Type definitions for once v1.3.3
+// Type definitions for once 1.4
 // Project: https://github.com/isaacs/once
 // Definitions by: Denis Sokolov <https://github.com/denis-sokolov>
+//                 BendingBender <https://github.com/BendingBender>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
-interface SimpleFunction<Result> {
-  (...args: any[]): Result;
+export = once;
+
+declare const once: Once;
+
+interface Once extends once.OnceFn {
+    proto(): void;
+    strict: once.OnceFn;
 }
 
-interface OnceFunction<Result> extends SimpleFunction<Result> {
-  called: boolean;
-  value: Result;
+declare namespace once {
+    interface OnceFn {
+        <R>(f: () => R): (() => R) & FnProps<R>;
+        <T1, R>(f: (t1: T1) => R): ((t1: T1) => R) & FnProps<R>;
+        <T1, T2, R>(f: (t1: T1, t2: T2) => R): ((t1: T1, t2: T2) => R) & FnProps<R>;
+        <T1, T2, T3, R>(f: (t1: T1, t2: T2, t3: T3) => R): ((t1: T1, t2: T2, t3: T3) => R) & FnProps<R>;
+        <T1, T2, T3, T4, R>(f: (t1: T1, t2: T2, t3: T3, t4: T4) => R): ((t1: T1, t2: T2, t3: T3, t4: T4) => R) & FnProps<R>;
+        <T1, T2, T3, T4, T5, R>(f: (t1: T1, t2: T2, t3: T3, t4: T4, t5: T5) => R): ((t1: T1, t2: T2, t3: T3, t4: T4, t5: T5) => R) & FnProps<R>;
+        <T1, T2, T3, T4, T5, T6, R>(f: (t1: T1, t2: T2, t3: T3, t4: T4, t5: T5, t6: T6) => R):
+            ((t1: T1, t2: T2, t3: T3, t4: T4, t5: T5, t6: T6) => R) & FnProps<R>;
+        <T1, T2, T3, T4, T5, T6, T7, R>(f: (t1: T1, t2: T2, t3: T3, t4: T4, t5: T5, t6: T6, t7: T7) => R):
+            ((t1: T1, t2: T2, t3: T3, t4: T4, t5: T5, t6: T6, t7: T7) => R) & FnProps<R>;
+        <T1, T2, T3, T4, T5, T6, T7, T8, R>(f: (t1: T1, t2: T2, t3: T3, t4: T4, t5: T5, t6: T6, t7: T7, t8: T8) => R):
+            ((t1: T1, t2: T2, t3: T3, t4: T4, t5: T5, t6: T6, t7: T7, t8: T8) => R) & FnProps<R>;
+        <T1, T2, T3, T4, T5, T6, T7, T8, T9, R>(f: (t1: T1, t2: T2, t3: T3, t4: T4, t5: T5, t6: T6, t7: T7, t8: T8, t9: T9) => R):
+            ((t1: T1, t2: T2, t3: T3, t4: T4, t5: T5, t6: T6, t7: T7, t8: T8, t9: T9) => R) & FnProps<R>;
+        <T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, R>(f: (t1: T1, t2: T2, t3: T3, t4: T4, t5: T5, t6: T6, t7: T7, t8: T8, t9: T9, t10: T10) => R):
+            ((t1: T1, t2: T2, t3: T3, t4: T4, t5: T5, t6: T6, t7: T7, t8: T8, t9: T9, t10: T10) => R) & FnProps<R>;
+        <R>(f: (...args: any[]) => R): ((...args: any[]) => R) & FnProps<R>;
+    }
+
+    interface FnProps<R> {
+        called: boolean;
+        value: R | undefined;
+    }
 }
 
-interface Once {
-  <Result>(f: SimpleFunction<Result>): OnceFunction<Result>;
-  proto: Function;
-}
-
-declare module "once" {
-  var once: Once;
-  export default once;
+declare global {
+    interface Function {
+        // tslint:disable-next-line ban-types
+        once(): Function & once.FnProps<any>;
+    }
 }
diff --git a/types/once/once-tests.ts b/types/once/once-tests.ts
index a7931aced2..cfca6a8f6a 100644
--- a/types/once/once-tests.ts
+++ b/types/once/once-tests.ts
@@ -1,13 +1,53 @@
+import once = require('once');
 
-
-import once from "once";
-
+// $ExpectType (() => number) & FnProps<number>
 once(() => 3);
-once(() => 3)();
-let s = once(() => ({foo: 1}))();
-s.foo;
+// $ExpectType ((t1: string) => number) & FnProps<number>
+once((t1: string) => 3);
+// $ExpectType ((t1: string, t2: null) => number) & FnProps<number>
+once((t1: string, t2: null) => 3);
+// $ExpectType ((t1: string, t2: null, t3: string) => number) & FnProps<number>
+once((t1: string, t2: null, t3: string) => 3);
+// $ExpectType ((t1: string, t2: null, t3: string, t4: null) => number) & FnProps<number>
+once((t1: string, t2: null, t3: string, t4: null) => 3);
+// $ExpectType ((t1: string, t2: null, t3: string, t4: null, t5: number) => number) & FnProps<number>
+once((t1: string, t2: null, t3: string, t4: null, t5: number) => 3);
+// $ExpectType ((t1: string, t2: null, t3: string, t4: null, t5: number, t6: null) => number) & FnProps<number>
+once((t1: string, t2: null, t3: string, t4: null, t5: number, t6: null) => 3);
+// $ExpectType ((t1: string, t2: null, t3: string, t4: null, t5: number, t6: null, t7: string) => number) & FnProps<number>
+once((t1: string, t2: null, t3: string, t4: null, t5: number, t6: null, t7: string) => 3);
+// $ExpectType ((t1: string, t2: null, t3: string, t4: null, t5: number, t6: null, t7: string, t8: null) => number) & FnProps<number>
+once((t1: string, t2: null, t3: string, t4: null, t5: number, t6: null, t7: string, t8: null) => 3);
+// $ExpectType ((t1: string, t2: null, t3: string, t4: null, t5: number, t6: null, t7: string, t8: null, t9: string) => number) & FnProps<number>
+once((t1: string, t2: null, t3: string, t4: null, t5: number, t6: null, t7: string, t8: null, t9: string) => 3);
+// $ExpectType ((t1: string, t2: null, t3: string, t4: null, t5: number, t6: null, t7: string, t8: null, t9: string, t10: null) => number) & FnProps<number>
+once((t1: string, t2: null, t3: string, t4: null, t5: number, t6: null, t7: string, t8: null, t9: string, t10: null) => 3);
+// $ExpectType ((...args: any[]) => number) & FnProps<number>
+once((t1: string, t2: null, t3: string, t4: null, t5: number, t6: null, t7: string, t8: null, t9: string, t10: null, t11: string) => 3);
+
+once(() => 3)(); // $ExpectType number
+once(() => ({foo: 1}))(); // $ExpectType { foo: number; }
+
+once(() => 3).called; // $ExpectType boolean
+once(() => ({foo: 1})).value; // $ExpectType { foo: number; } | undefined
 
 once.proto();
 
-once(() => 3).called && true;
-once(() => ({foo: 1})).value.foo;
+once.strict(() => 3); // $ExpectType (() => number) & FnProps<number>
+
+Function.prototype.once; // ExpectType () => Function & once.FnProps<any>;
+function fn() {
+    return 3;
+}
+fn.once(); // $ExpectType Function & FnProps<any>
+
+function greet(name: string | null, cb: (greeting: string) => void) {
+    if (!name) cb('Hello anonymous');
+    cb('Hello ' + name);
+}
+function log(msg: any) {
+}
+// this will print 'Hello anonymous' but the logical error will be missed
+greet(null, once(log));
+// once.strict will print 'Hello anonymous' and throw an error when the callback will be called the second time
+greet(null, once.strict(log));
diff --git a/types/once/tsconfig.json b/types/once/tsconfig.json
index eb26ee77e7..4da17e3d3b 100644
--- a/types/once/tsconfig.json
+++ b/types/once/tsconfig.json
@@ -6,7 +6,7 @@
         ],
         "noImplicitAny": true,
         "noImplicitThis": true,
-        "strictNullChecks": false,
+        "strictNullChecks": true,
         "baseUrl": "../",
         "typeRoots": [
             "../"
@@ -19,4 +19,4 @@
         "index.d.ts",
         "once-tests.ts"
     ]
-}
\ No newline at end of file
+}
diff --git a/types/once/tslint.json b/types/once/tslint.json
new file mode 100644
index 0000000000..3db14f85ea
--- /dev/null
+++ b/types/once/tslint.json
@@ -0,0 +1 @@
+{ "extends": "dtslint/dt.json" }