diff --git a/src/lib/es5.d.ts b/src/lib/es5.d.ts
index 7dfccb327ea41..98db54f39bb93 100644
--- a/src/lib/es5.d.ts
+++ b/src/lib/es5.d.ts
@@ -1443,10 +1443,17 @@ type Exclude<T, U> = T extends U ? never : T;
  */
 type Extract<T, U> = T extends U ? T : never;
 
+type KnownKeys<T> = {
+    [K in keyof T]: string extends K ? never : number extends K ? never : K
+} extends { [_ in keyof T]: infer U } ? ({} extends U ? never : U) : never;
+type OmitFromKnownKeys<T, K extends keyof T> = KnownKeys<T> extends infer U ?
+    [U] extends [keyof T] ? Pick<T, Exclude<U, K>> : never : never;
 /**
  * Construct a type with the properties of T except for those in type K.
  */
-type Omit<T, K extends keyof any> = Pick<T, Exclude<keyof T, K>>;
+type Omit<T, K extends keyof T> = OmitFromKnownKeys<T, K>
+    & (string extends K ? {} : (string extends keyof T ? { [n: string]: T[Exclude<keyof T, number>]} : {}))
+    & (number extends K ? {} : (number extends keyof T ? { [n: number]: T[Exclude<keyof T, string>]} : {}));
 
 /**
  * Exclude null and undefined from T