diff --git a/lib/deep-equal.js b/lib/deep-equal.js
index ce0c8c8..88156e0 100644
--- a/lib/deep-equal.js
+++ b/lib/deep-equal.js
@@ -200,10 +200,6 @@ function deepEqualCyclic(actual, expectation, match) {
             !isArrayType(expectation) &&
             !isArguments(expectation);
         if (isActualNonArrayIterable || isExpectationNonArrayIterable) {
-            if (!isActualNonArrayIterable || !isExpectationNonArrayIterable) {
-                return false;
-            }
-
             var actualArray = Array.from(actualObj);
             var expectationArray = Array.from(expectation);
             if (actualArray.length !== expectationArray.length) {
diff --git a/lib/is-iterable.test.js b/lib/is-iterable.test.js
new file mode 100644
index 0000000..009f215
--- /dev/null
+++ b/lib/is-iterable.test.js
@@ -0,0 +1,30 @@
+"use strict";
+
+var assert = require("@sinonjs/referee").assert;
+var isIterable = require("./is-iterable");
+
+describe("isIterable", function () {
+    it("returns false if not object", function () {
+        assert.isFalse(isIterable(undefined));
+    });
+
+    it("returns false if object does not have iterator function", function () {
+        assert.isFalse(isIterable({}));
+    });
+
+    it("returns true if Set", function () {
+        assert.isTrue(isIterable(new Set()));
+    });
+
+    it("returns true if Set iterator", function () {
+        assert.isTrue(isIterable(new Set().values()));
+    });
+
+    it("returns true if Map", function () {
+        assert.isTrue(isIterable(new Map()));
+    });
+
+    it("returns true if Map iterator", function () {
+        assert.isTrue(isIterable(new Map().values()));
+    });
+});