diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7d5ecb252..a1523f422 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,11 @@
 **Note**: Gaps between patch versions are faulty/broken releases. **Note**: A feature tagged as Experimental is in a
 high state of flux, you're at risk of it changing without notice.
 
+# 2.0.6
+
+- **Bug Fix**
+  - whitelist `window` in `UnknownRecord`, fix #413 (@gcanti)
+
 # 2.0.5
 
 - **Bug Fix**
diff --git a/dtslint/ts3.5/index.ts b/dtslint/ts3.5/index.ts
index 549404c29..69c1cbc19 100644
--- a/dtslint/ts3.5/index.ts
+++ b/dtslint/ts3.5/index.ts
@@ -10,7 +10,7 @@ type Compact<A> = { [K in keyof A]: A[K] }
 /**
  * Returns the string literal 'T' if `A` and `B` are equal types, 'F' otherwise
  */
-type Equals<A, B> = (<C>() => C extends Compact<A> ? 'T' : 'F') extends (<C>() => C extends Compact<B> ? 'T' : 'F')
+type Equals<A, B> = (<C>() => C extends Compact<A> ? 'T' : 'F') extends <C>() => C extends Compact<B> ? 'T' : 'F'
   ? 'T'
   : 'F'
 
@@ -582,3 +582,20 @@ const toNumber = (n: t.Int): number => n
 
 // $ExpectError
 const intToInt2 = (int: t.Int): Int2 => int
+
+//
+// UnknownRecord
+//
+
+// $ExpectError
+const ur1: Record<string, unknown> = [1, 2, 3]
+// $ExpectError
+const ur2: Record<string, unknown> = new Date()
+// tslint:disable: no-construct
+// $ExpectError
+const ur3: Record<string, unknown> = new Number()
+// $ExpectError
+const ur4: Record<string, unknown> = new String()
+// $ExpectError
+const ur5: Record<string, unknown> = new Boolean()
+// tslint:enable: no-construct
diff --git a/package.json b/package.json
index 33e62ee19..97766aac8 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "io-ts",
-  "version": "2.0.5",
+  "version": "2.0.6",
   "description": "TypeScript compatible runtime type system for IO validation",
   "files": [
     "lib",
diff --git a/src/index.ts b/src/index.ts
index 518882320..d1e527479 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -416,7 +416,10 @@ export class AnyDictionaryType extends Type<{ [key: string]: unknown }> {
   constructor() {
     super(
       'UnknownRecord',
-      (u): u is { [key: string]: unknown } => Object.prototype.toString.call(u) === '[object Object]',
+      (u): u is { [key: string]: unknown } => {
+        const s = Object.prototype.toString.call(u)
+        return s === '[object Object]' || s === '[object Window]'
+      },
       (u, c) => (this.is(u) ? success(u) : failure(u, c)),
       identity
     )