if in strict mode, constructor must match

README.md

@@ -4,7 +4,7 @@
 <img src="https://img.shields.io/badge/coverage-100%25-brightgreen.svg"/>
 <img src="https://img.shields.io/badge/license-MIT-blue.svg"/>
 
-Perform [blazing fast](#benchmarks) equality comparisons (either deep or shallow) on two objects passed. It has no dependencies, and is ~1.64kB when minified and gzipped.
+Perform [blazing fast](#benchmarks) equality comparisons (either deep or shallow) on two objects passed. It has no dependencies, and is ~1.75kB when minified and gzipped.
 
 Unlike most equality validation libraries, the following types are handled out-of-the-box:
 
@@ -162,6 +162,7 @@ console.log(circularShallowEqual(array, [array])); // false
 
 Performs the same comparison as `deepEqual` but performs a strict comparison of the objects. In this includes:
 
+- Checking constructors match
 - Checking non-enumerable properties in object comparisons
 - Checking full descriptor of properties on the object to match
 - Checking non-index properties on arrays

src/comparator.ts

@@ -63,6 +63,10 @@ export function createComparator<Meta>({
       return a !== a && b !== b;
     }
 
+    if (state.strict && a.constructor !== b.constructor) {
+      return false;
+    }
+
     // Checks are listed in order of commonality of use-case:
     //   1. Common complex object types (plain object, array)
     //   2. Common data values (date, regexp)