diff --git a/types/screenfull/index.d.ts b/types/screenfull/index.d.ts
index 0ca3d642b9..2c7b93e453 100644
--- a/types/screenfull/index.d.ts
+++ b/types/screenfull/index.d.ts
@@ -1,36 +1,85 @@
-// Type definitions for screenfull.js 3.3.3
+// Type definitions for screenfull.js 4.0
 // Project: https://github.com/sindresorhus/screenfull.js
 // Definitions by: Ilia Choly <https://github.com/icholy>
 //                 lionelb <https://github.com/lionelb>
 //                 Joel Shepherd <https://github.com/joelshepherd>
+//                 BendingBender <https://github.com/BendingBender>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.5
 
-declare var screenfull: IScreenfull | false;
-
-interface IScreenfullRaw {
-  requestFullscreen?: string;
-  exitFullscreen?: string;
-  fullscreenElement?: string;
-  fullscreenEnabled?: string;
-  fullscreenchange?: string;
-  fullscreenerror?: string;
-}
-
-interface IScreenfull {
-  isFullscreen: boolean;
-  element: Element;
-  enabled: boolean;
-  raw: IScreenfullRaw;
-  request(elem?: Element): void;
-  toggle(elem?: Element): void;
-  exit(): void;
-  onchange(handler: () => void): void;
-  onerror(handler: (event: Event) => void): void;
-  on(name: EventNameMap, handler: (event: Event) => void): void;
-  off(name: EventNameMap, handler: (event: Event) => void): void;
-}
-
-type EventNameMap = 'change' | 'error';
-
 export = screenfull;
+export as namespace screenfull;
+
+declare const screenfull: screenfull.Screenfull | false;
+
+declare namespace screenfull {
+    interface Screenfull {
+        /**
+         * Returns a boolean whether fullscreen is active.
+         */
+        readonly isFullscreen: boolean;
+        /**
+         * Returns the element currently in fullscreen, otherwise `null`.
+         */
+        readonly element: Element | null;
+        /**
+         * Returns a boolean whether you are allowed to enter fullscreen. If your page is inside an `<iframe>`
+         * you will need to add a `allowfullscreen` attribute (+ `webkitallowfullscreen` and `mozallowfullscreen`).
+         */
+        readonly enabled: boolean;
+        /**
+         * Exposes the raw properties (prefixed if needed) used internally.
+         */
+        raw: RawEventNames;
+        /**
+         * Make an element fullscreen.
+         *
+         * If your page is inside an `<iframe>` you will need to add a `allowfullscreen` attribute
+         * (+ `webkitallowfullscreen` and `mozallowfullscreen`).
+         *
+         * Keep in mind that the browser will only enter fullscreen when initiated by user events like click, touch, key.
+         *
+         * @param element Default is `<html>`. If called with another element than the currently active,
+         * it will switch to that if it's a decendant.
+         * @returns A promise that resolves after the element enters fullscreen.
+         */
+        request(element?: Element): Promise<void>;
+        /**
+         * Brings you out of fullscreen.
+         * @returns A promise that resolves after the element exits fullscreen.
+         */
+        exit(): Promise<void>;
+        /**
+         * Requests fullscreen if not active, otherwise exits.
+         * @returns A promise that resolves after the element enters/exits fullscreen.
+         */
+        toggle(elem?: Element): Promise<void>;
+        /**
+         * Add a listener for when the browser switches in and out of fullscreen or when there is an error.
+         */
+        on(name: EventName, handler: (event: Event) => void): void;
+        /**
+         * Remove a previously registered event listener.
+         */
+        off(name: EventName, handler: (event: Event) => void): void;
+        /**
+         * Alias for `.on('change', function)`.
+         */
+        onchange(handler: (event: Event) => void): void;
+        /**
+         * Alias for `.on('error', function)`.
+         */
+        onerror(handler: (event: Event) => void): void;
+    }
+
+    interface RawEventNames {
+        requestFullscreen: string;
+        exitFullscreen: string;
+        fullscreenElement: string;
+        fullscreenEnabled: string;
+        fullscreenchange: string;
+        fullscreenerror: string;
+    }
+
+    type EventName = 'change' | 'error';
+}
diff --git a/types/screenfull/screenfull-tests.ts b/types/screenfull/screenfull-tests.ts
index db6f2a1b25..3bc509fd53 100644
--- a/types/screenfull/screenfull-tests.ts
+++ b/types/screenfull/screenfull-tests.ts
@@ -1,112 +1,46 @@
 import screenfull = require('screenfull');
 
-function test_fullscreen_page() {
-  if (screenfull && screenfull.enabled) {
-    screenfull.request();
-  }
-}
+if (screenfull) {
+    screenfull.enabled; // $ExpectType boolean
+    screenfull.enabled = false; // $ExpectError
+    screenfull.isFullscreen; // $ExpectType boolean
+    screenfull.isFullscreen = false; // $ExpectError
+    screenfull.element; // $ExpectType Element | null
+    screenfull.element = document.documentElement; // $ExpectError
 
-function test_fullscreen_element() {
-  var elem = document.getElementById('target');
-  if (screenfull && screenfull.enabled) {
-    screenfull.request(elem);
-  }
-}
+    if (screenfull.enabled) {
+        const elem: Element = document.getElementById('target')!;
 
-function test_toggle() {
-  var elem = document.getElementById('target');
-  if (screenfull && screenfull.enabled) {
-    screenfull.toggle(elem);
-  }
-}
+        screenfull.request(); // $ExpectType Promise<void>
+        screenfull.request(elem); // $ExpectType Promise<void>
+        screenfull.toggle(); // $ExpectType Promise<void>
+        screenfull.toggle(elem); // $ExpectType Promise<void>
+        screenfull.exit(); // $ExpectType Promise<void>
 
-function test_exit() {
-  if (screenfull && screenfull.enabled) {
-    screenfull.request();
-  }
-  document.getElementById('target').addEventListener('click', function () {
-    if (screenfull && screenfull.enabled) {
-      screenfull.exit();
+        screenfull.on('change', event => {
+            event; // $ExpectType Event
+        });
+        screenfull.on('error', event => {
+            event; // $ExpectType Event
+        });
+        screenfull.off('change', event => {
+            event; // $ExpectType Event
+        });
+        screenfull.off('error', event => {
+            event; // $ExpectType Event
+        });
+        screenfull.onchange(event => {
+            event; // $ExpectType Event
+        });
+        screenfull.onerror(event => {
+            event; // $ExpectType Event
+        });
+
+        screenfull.raw.requestFullscreen; // $ExpectType string
+        screenfull.raw.exitFullscreen; // $ExpectType string
+        screenfull.raw.fullscreenElement; // $ExpectType string
+        screenfull.raw.fullscreenEnabled; // $ExpectType string
+        screenfull.raw.fullscreenchange; // $ExpectType string
+        screenfull.raw.fullscreenerror; // $ExpectType string
     }
-  })
-}
-
-function test_raw_detect_change() {
-  if (screenfull && screenfull.enabled) {
-    document.addEventListener(screenfull.raw.fullscreenchange, function () {
-      if (screenfull && screenfull.isFullscreen) {
-        console.log('fullscreen');
-      } else {
-        console.log('not fullscreen');
-      }
-    });
-  }
-}
-
-function test_raw_error() {
-  if (screenfull && screenfull.enabled) {
-    document.addEventListener(screenfull.raw.fullscreenerror, function (event) {
-      console.error('Failed to enable fullscreen', event);
-    });
-  }
-}
-
-function test_detect_change() {
-  if (screenfull && screenfull.enabled) {
-    screenfull.onchange(function () {
-      if (screenfull && screenfull.isFullscreen) {
-        console.log('fullscreen');
-      } else {
-        console.log('not fullscreen');
-      }
-    });
-  }
-}
-
-function test_detect_error() {
-  if (screenfull && screenfull.enabled) {
-    screenfull.onerror(function (event) {
-      console.error('Failed to enable fullscreen', event);
-    });
-  }
-}
-
-function test_listener_on() {
-  if (screenfull && screenfull.enabled) {
-    screenfull.on('change', function () {
-      if (screenfull && screenfull.isFullscreen) {
-        console.log('fullscreen');
-      } else {
-        console.log('not fullscreen');
-      }
-    });
-    screenfull.on('error', function (event) {
-      console.error('Failed to enable fullscreen', event);
-    })
-  }
-}
-
-function test_listener_off() {
-  if (screenfull && screenfull.enabled) {
-    screenfull.off('change', function () {
-      if (screenfull && screenfull.isFullscreen) {
-        console.log('fullscreen');
-      } else {
-        console.log('not fullscreen');
-      }
-    });
-    screenfull.off('error', function (event) {
-      console.error('Failed to enable fullscreen', event);
-    })
-  }
-}
-
-function test_access_element() {
-  var elem = document.getElementById('target');
-  if (screenfull && screenfull.enabled) {
-    screenfull.request(elem);
-    if (elem !== screenfull.element) {
-      alert('incorrect element property');
-    }
-  }
 }
diff --git a/types/screenfull/tsconfig.json b/types/screenfull/tsconfig.json
index 87cb31765a..e3073a5338 100644
--- a/types/screenfull/tsconfig.json
+++ b/types/screenfull/tsconfig.json
@@ -7,7 +7,7 @@
         ],
         "noImplicitAny": true,
         "noImplicitThis": true,
-        "strictNullChecks": false,
+        "strictNullChecks": true,
         "strictFunctionTypes": true,
         "baseUrl": "../",
         "typeRoots": [
@@ -21,4 +21,4 @@
         "index.d.ts",
         "screenfull-tests.ts"
     ]
-}
\ No newline at end of file
+}
diff --git a/types/screenfull/tslint.json b/types/screenfull/tslint.json
index a41bf5d19a..f93cf8562a 100644
--- a/types/screenfull/tslint.json
+++ b/types/screenfull/tslint.json
@@ -1,79 +1,3 @@
 {
-    "extends": "dtslint/dt.json",
-    "rules": {
-        "adjacent-overload-signatures": false,
-        "array-type": false,
-        "arrow-return-shorthand": false,
-        "ban-types": false,
-        "callable-types": false,
-        "comment-format": false,
-        "dt-header": false,
-        "eofline": false,
-        "export-just-namespace": false,
-        "import-spacing": false,
-        "interface-name": false,
-        "interface-over-type-literal": false,
-        "jsdoc-format": false,
-        "max-line-length": false,
-        "member-access": false,
-        "new-parens": false,
-        "no-any-union": false,
-        "no-boolean-literal-compare": false,
-        "no-conditional-assignment": false,
-        "no-consecutive-blank-lines": false,
-        "no-construct": false,
-        "no-declare-current-package": false,
-        "no-duplicate-imports": false,
-        "no-duplicate-variable": false,
-        "no-empty-interface": false,
-        "no-for-in-array": false,
-        "no-inferrable-types": false,
-        "no-internal-module": false,
-        "no-irregular-whitespace": false,
-        "no-mergeable-namespace": false,
-        "no-misused-new": false,
-        "no-namespace": false,
-        "no-object-literal-type-assertion": false,
-        "no-padding": false,
-        "no-redundant-jsdoc": false,
-        "no-redundant-jsdoc-2": false,
-        "no-redundant-undefined": false,
-        "no-reference-import": false,
-        "no-relative-import-in-test": false,
-        "no-self-import": false,
-        "no-single-declare-module": false,
-        "no-string-throw": false,
-        "no-unnecessary-callback-wrapper": false,
-        "no-unnecessary-class": false,
-        "no-unnecessary-generics": false,
-        "no-unnecessary-qualifier": false,
-        "no-unnecessary-type-assertion": false,
-        "no-useless-files": false,
-        "no-var-keyword": false,
-        "no-var-requires": false,
-        "no-void-expression": false,
-        "no-trailing-whitespace": false,
-        "object-literal-key-quotes": false,
-        "object-literal-shorthand": false,
-        "one-line": false,
-        "one-variable-per-declaration": false,
-        "only-arrow-functions": false,
-        "prefer-conditional-expression": false,
-        "prefer-const": false,
-        "prefer-declare-function": false,
-        "prefer-for-of": false,
-        "prefer-method-signature": false,
-        "prefer-template": false,
-        "radix": false,
-        "semicolon": false,
-        "space-before-function-paren": false,
-        "space-within-parens": false,
-        "strict-export-declare-modifiers": false,
-        "trim-file": false,
-        "triple-equals": false,
-        "typedef-whitespace": false,
-        "unified-signatures": false,
-        "void-return": false,
-        "whitespace": false
-    }
+    "extends": "dtslint/dt.json"
 }
diff --git a/types/screenfull/v3/index.d.ts b/types/screenfull/v3/index.d.ts
new file mode 100644
index 0000000000..0ca3d642b9
--- /dev/null
+++ b/types/screenfull/v3/index.d.ts
@@ -0,0 +1,36 @@
+// Type definitions for screenfull.js 3.3.3
+// Project: https://github.com/sindresorhus/screenfull.js
+// Definitions by: Ilia Choly <https://github.com/icholy>
+//                 lionelb <https://github.com/lionelb>
+//                 Joel Shepherd <https://github.com/joelshepherd>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.5
+
+declare var screenfull: IScreenfull | false;
+
+interface IScreenfullRaw {
+  requestFullscreen?: string;
+  exitFullscreen?: string;
+  fullscreenElement?: string;
+  fullscreenEnabled?: string;
+  fullscreenchange?: string;
+  fullscreenerror?: string;
+}
+
+interface IScreenfull {
+  isFullscreen: boolean;
+  element: Element;
+  enabled: boolean;
+  raw: IScreenfullRaw;
+  request(elem?: Element): void;
+  toggle(elem?: Element): void;
+  exit(): void;
+  onchange(handler: () => void): void;
+  onerror(handler: (event: Event) => void): void;
+  on(name: EventNameMap, handler: (event: Event) => void): void;
+  off(name: EventNameMap, handler: (event: Event) => void): void;
+}
+
+type EventNameMap = 'change' | 'error';
+
+export = screenfull;
diff --git a/types/screenfull/v3/screenfull-tests.ts b/types/screenfull/v3/screenfull-tests.ts
new file mode 100644
index 0000000000..db6f2a1b25
--- /dev/null
+++ b/types/screenfull/v3/screenfull-tests.ts
@@ -0,0 +1,112 @@
+import screenfull = require('screenfull');
+
+function test_fullscreen_page() {
+  if (screenfull && screenfull.enabled) {
+    screenfull.request();
+  }
+}
+
+function test_fullscreen_element() {
+  var elem = document.getElementById('target');
+  if (screenfull && screenfull.enabled) {
+    screenfull.request(elem);
+  }
+}
+
+function test_toggle() {
+  var elem = document.getElementById('target');
+  if (screenfull && screenfull.enabled) {
+    screenfull.toggle(elem);
+  }
+}
+
+function test_exit() {
+  if (screenfull && screenfull.enabled) {
+    screenfull.request();
+  }
+  document.getElementById('target').addEventListener('click', function () {
+    if (screenfull && screenfull.enabled) {
+      screenfull.exit();
+    }
+  })
+}
+
+function test_raw_detect_change() {
+  if (screenfull && screenfull.enabled) {
+    document.addEventListener(screenfull.raw.fullscreenchange, function () {
+      if (screenfull && screenfull.isFullscreen) {
+        console.log('fullscreen');
+      } else {
+        console.log('not fullscreen');
+      }
+    });
+  }
+}
+
+function test_raw_error() {
+  if (screenfull && screenfull.enabled) {
+    document.addEventListener(screenfull.raw.fullscreenerror, function (event) {
+      console.error('Failed to enable fullscreen', event);
+    });
+  }
+}
+
+function test_detect_change() {
+  if (screenfull && screenfull.enabled) {
+    screenfull.onchange(function () {
+      if (screenfull && screenfull.isFullscreen) {
+        console.log('fullscreen');
+      } else {
+        console.log('not fullscreen');
+      }
+    });
+  }
+}
+
+function test_detect_error() {
+  if (screenfull && screenfull.enabled) {
+    screenfull.onerror(function (event) {
+      console.error('Failed to enable fullscreen', event);
+    });
+  }
+}
+
+function test_listener_on() {
+  if (screenfull && screenfull.enabled) {
+    screenfull.on('change', function () {
+      if (screenfull && screenfull.isFullscreen) {
+        console.log('fullscreen');
+      } else {
+        console.log('not fullscreen');
+      }
+    });
+    screenfull.on('error', function (event) {
+      console.error('Failed to enable fullscreen', event);
+    })
+  }
+}
+
+function test_listener_off() {
+  if (screenfull && screenfull.enabled) {
+    screenfull.off('change', function () {
+      if (screenfull && screenfull.isFullscreen) {
+        console.log('fullscreen');
+      } else {
+        console.log('not fullscreen');
+      }
+    });
+    screenfull.off('error', function (event) {
+      console.error('Failed to enable fullscreen', event);
+    })
+  }
+}
+
+function test_access_element() {
+  var elem = document.getElementById('target');
+  if (screenfull && screenfull.enabled) {
+    screenfull.request(elem);
+    if (elem !== screenfull.element) {
+      alert('incorrect element property');
+    }
+  }
+}
diff --git a/types/screenfull/v3/tsconfig.json b/types/screenfull/v3/tsconfig.json
new file mode 100644
index 0000000000..0bceb56930
--- /dev/null
+++ b/types/screenfull/v3/tsconfig.json
@@ -0,0 +1,29 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6",
+            "dom"
+        ],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictNullChecks": false,
+        "strictFunctionTypes": true,
+        "baseUrl": "../../",
+        "typeRoots": [
+            "../../"
+        ],
+        "paths": {
+            "screenfull": [
+                "screenfull/v3"
+            ]
+        },
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+        "screenfull-tests.ts"
+    ]
+}
diff --git a/types/screenfull/v3/tslint.json b/types/screenfull/v3/tslint.json
new file mode 100644
index 0000000000..a41bf5d19a
--- /dev/null
+++ b/types/screenfull/v3/tslint.json
@@ -0,0 +1,79 @@
+{
+    "extends": "dtslint/dt.json",
+    "rules": {
+        "adjacent-overload-signatures": false,
+        "array-type": false,
+        "arrow-return-shorthand": false,
+        "ban-types": false,
+        "callable-types": false,
+        "comment-format": false,
+        "dt-header": false,
+        "eofline": false,
+        "export-just-namespace": false,
+        "import-spacing": false,
+        "interface-name": false,
+        "interface-over-type-literal": false,
+        "jsdoc-format": false,
+        "max-line-length": false,
+        "member-access": false,
+        "new-parens": false,
+        "no-any-union": false,
+        "no-boolean-literal-compare": false,
+        "no-conditional-assignment": false,
+        "no-consecutive-blank-lines": false,
+        "no-construct": false,
+        "no-declare-current-package": false,
+        "no-duplicate-imports": false,
+        "no-duplicate-variable": false,
+        "no-empty-interface": false,
+        "no-for-in-array": false,
+        "no-inferrable-types": false,
+        "no-internal-module": false,
+        "no-irregular-whitespace": false,
+        "no-mergeable-namespace": false,
+        "no-misused-new": false,
+        "no-namespace": false,
+        "no-object-literal-type-assertion": false,
+        "no-padding": false,
+        "no-redundant-jsdoc": false,
+        "no-redundant-jsdoc-2": false,
+        "no-redundant-undefined": false,
+        "no-reference-import": false,
+        "no-relative-import-in-test": false,
+        "no-self-import": false,
+        "no-single-declare-module": false,
+        "no-string-throw": false,
+        "no-unnecessary-callback-wrapper": false,
+        "no-unnecessary-class": false,
+        "no-unnecessary-generics": false,
+        "no-unnecessary-qualifier": false,
+        "no-unnecessary-type-assertion": false,
+        "no-useless-files": false,
+        "no-var-keyword": false,
+        "no-var-requires": false,
+        "no-void-expression": false,
+        "no-trailing-whitespace": false,
+        "object-literal-key-quotes": false,
+        "object-literal-shorthand": false,
+        "one-line": false,
+        "one-variable-per-declaration": false,
+        "only-arrow-functions": false,
+        "prefer-conditional-expression": false,
+        "prefer-const": false,
+        "prefer-declare-function": false,
+        "prefer-for-of": false,
+        "prefer-method-signature": false,
+        "prefer-template": false,
+        "radix": false,
+        "semicolon": false,
+        "space-before-function-paren": false,
+        "space-within-parens": false,
+        "strict-export-declare-modifiers": false,
+        "trim-file": false,
+        "triple-equals": false,
+        "typedef-whitespace": false,
+        "unified-signatures": false,
+        "void-return": false,
+        "whitespace": false
+    }
+}
