diff --git a/types/assert/assert-tests.ts b/types/assert/assert-tests.ts
index 3f795f0552..a2ebffefea 100644
--- a/types/assert/assert-tests.ts
+++ b/types/assert/assert-tests.ts
@@ -2,10 +2,14 @@ import * as assert from 'assert';
 
 assert(true, "it's working");
 
-assert.ok(true, "inner functions work as well");
+assert.ok(true, 'inner functions work as well');
 
 assert.throws(() => {});
 assert.throws(() => {}, /Regex test/);
-assert.throws(() => {}, () => {}, "works wonderfully");
+assert.throws(
+    () => {},
+    () => {},
+    'works wonderfully',
+);
 
-assert['fail'](true, true, "works like a charm");
+assert['fail'](true, true, 'works like a charm');
diff --git a/types/assert/index.d.ts b/types/assert/index.d.ts
index f436b7b4fd..9ae05ce63f 100644
--- a/types/assert/index.d.ts
+++ b/types/assert/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/browserify/commonjs-assert, https://github.com/defunctzombie/commonjs-assert
 // Definitions by: Nico Gallinal <https://github.com/nicoabie>
 //                 Linus Unnebäck <https://github.com/LinusU>
+//                 ExE Boss <https://github.com/ExE-Boss>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
 declare function assert(value: any, message?: string): void;
@@ -29,7 +30,11 @@ declare namespace assert {
     function throws(block: () => void, error: (() => void) | ((err: any) => boolean) | RegExp, message?: string): void;
 
     function doesNotThrow(block: () => void, message?: string): void;
-    function doesNotThrow(block: () => void, error: (() => void) | ((err: any) => boolean) | RegExp, message?: string): void;
+    function doesNotThrow(
+        block: () => void,
+        error: (() => void) | ((err: any) => boolean) | RegExp,
+        message?: string,
+    ): void;
 
     function ifError(value: any): void;
 
@@ -41,7 +46,13 @@ declare namespace assert {
         operator: string;
         generatedMessage: boolean;
 
-        constructor(options?: { message?: string; actual?: any; expected?: any; operator?: string; stackStartFunction?: () => void });
+        constructor(options?: {
+            message?: string;
+            actual?: any;
+            expected?: any;
+            operator?: string;
+            stackStartFunction?: () => void;
+        });
     }
 }
 
diff --git a/types/assert/package.json b/types/assert/package.json
new file mode 100644
index 0000000000..f28600648d
--- /dev/null
+++ b/types/assert/package.json
@@ -0,0 +1,7 @@
+{
+    "private": true,
+    "types": "index",
+    "typesVersions": {
+        ">=3.7.0-0": { "*": ["ts3.7/*"] }
+    }
+}
diff --git a/types/assert/ts3.7/assert-tests.ts b/types/assert/ts3.7/assert-tests.ts
new file mode 100644
index 0000000000..983748c1fd
--- /dev/null
+++ b/types/assert/ts3.7/assert-tests.ts
@@ -0,0 +1,59 @@
+import * as assert from 'assert';
+
+assert(true, "it's working");
+
+assert.ok(true, 'inner functions work as well');
+
+assert.throws(() => {});
+assert.throws(() => {}, /Regex test/);
+assert.throws(
+    () => {},
+    () => {},
+    'works wonderfully',
+);
+
+assert['fail'](true, true, 'works like a charm');
+
+{
+    const a = null as any;
+    assert.ifError(a);
+    a; // $ExpectType null | undefined
+}
+
+{
+    const a = true as boolean;
+    assert(a);
+    a; // $ExpectType true
+}
+
+{
+    // tslint:disable-next-line: no-null-undefined-union
+    const a = 13 as number | null | undefined;
+    assert(a);
+    a; // $ExpectType number
+}
+
+{
+    const a = true as boolean;
+    assert.ok(a);
+    a; // $ExpectType true
+}
+
+{
+    // tslint:disable-next-line: no-null-undefined-union
+    const a = 13 as number | null | undefined;
+    assert.ok(a);
+    a; // $ExpectType number
+}
+
+{
+    const a = 'test' as any;
+    assert.strictEqual(a, 'test');
+    a; // $ExpectType string
+}
+
+{
+    const a = { b: 2 } as any;
+    assert.deepStrictEqual(a, { b: 2 });
+    a; // $ExpectType { b: number; }
+}
diff --git a/types/assert/ts3.7/index.d.ts b/types/assert/ts3.7/index.d.ts
new file mode 100644
index 0000000000..2e62d81566
--- /dev/null
+++ b/types/assert/ts3.7/index.d.ts
@@ -0,0 +1,58 @@
+declare function assert(value: any, message?: string): asserts value;
+
+declare namespace assert {
+    function fail(actual?: any, expected?: any, message?: string, operator?: string): void;
+
+    function ok(value: any, message?: string): asserts value;
+
+    /** @deprecated Use `strictEqual` instead */
+    function equal(actual: any, expected: any, message?: string): void;
+
+    /** @deprecated Use `notStrictEqual` instead */
+    function notEqual(actual: any, expected: any, message?: string): void;
+
+    /** @deprecated Use `deepStrictEqual` instead */
+    function deepEqual(actual: any, expected: any, message?: string): void;
+
+    /** @deprecated Use `notDeepStrictEqual` instead */
+    function notDeepEqual(actual: any, expected: any, message?: string): void;
+
+    function deepStrictEqual<T>(actual: any, expected: T, message?: string): asserts actual is T;
+
+    function notDeepStrictEqual(actual: any, expected: any, message?: string): void;
+
+    function strictEqual<T>(actual: any, expected: T, message?: string): asserts actual is T;
+
+    function notStrictEqual(actual: any, expected: any, message?: string): void;
+
+    function throws(block: () => void, message?: string): void;
+    function throws(block: () => void, error: (() => void) | ((err: any) => boolean) | RegExp, message?: string): void;
+
+    function doesNotThrow(block: () => void, message?: string): void;
+    function doesNotThrow(
+        block: () => void,
+        error: (() => void) | ((err: any) => boolean) | RegExp,
+        message?: string,
+    ): void;
+
+    function ifError(value: any): asserts value is null | undefined;
+
+    class AssertionError implements Error {
+        name: string;
+        message: string;
+        actual: any;
+        expected: any;
+        operator: string;
+        generatedMessage: boolean;
+
+        constructor(options?: {
+            message?: string;
+            actual?: any;
+            expected?: any;
+            operator?: string;
+            stackStartFunction?: () => void;
+        });
+    }
+}
+
+export = assert;
diff --git a/types/assert/ts3.7/tsconfig.json b/types/assert/ts3.7/tsconfig.json
new file mode 100644
index 0000000000..98c4f2a3e2
--- /dev/null
+++ b/types/assert/ts3.7/tsconfig.json
@@ -0,0 +1,19 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": ["es2015"],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictNullChecks": true,
+        "strictFunctionTypes": true,
+        "baseUrl": "../../",
+        "typeRoots": ["../../"],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "assert-tests.ts",
+        "index.d.ts"
+    ]
+}
diff --git a/types/assert/ts3.7/tslint.json b/types/assert/ts3.7/tslint.json
new file mode 100644
index 0000000000..3db14f85ea
--- /dev/null
+++ b/types/assert/ts3.7/tslint.json
@@ -0,0 +1 @@
+{ "extends": "dtslint/dt.json" }
diff --git a/types/assert/tsconfig.json b/types/assert/tsconfig.json
index 5ab217b2ab..e2f4f88baa 100644
--- a/types/assert/tsconfig.json
+++ b/types/assert/tsconfig.json
@@ -1,24 +1,19 @@
 {
     "compilerOptions": {
         "module": "commonjs",
-        "lib": [
-            "es6",
-            "dom"
-        ],
+        "lib": ["es2015"],
         "noImplicitAny": true,
         "noImplicitThis": true,
         "strictNullChecks": true,
         "strictFunctionTypes": true,
         "baseUrl": "../",
-        "typeRoots": [
-            "../"
-        ],
+        "typeRoots": ["../"],
         "types": [],
         "noEmit": true,
         "forceConsistentCasingInFileNames": true
     },
     "files": [
-        "index.d.ts",
-        "assert-tests.ts"
+        "assert-tests.ts",
+        "index.d.ts"
     ]
 }
diff --git a/types/assert/tslint.json b/types/assert/tslint.json
index f93cf8562a..3db14f85ea 100644
--- a/types/assert/tslint.json
+++ b/types/assert/tslint.json
@@ -1,3 +1 @@
-{
-    "extends": "dtslint/dt.json"
-}
+{ "extends": "dtslint/dt.json" }