diff --git a/lib/assert.js b/lib/assert.js
index afd5991ce..7190a34b7 100644
--- a/lib/assert.js
+++ b/lib/assert.js
@@ -75,7 +75,11 @@ x.throws = function (fn, err, msg) {
 				x.throws(noop, err, msg);
 			}, function (fnErr) {
 				x.throws(function () {
-					throw fnErr;
+					if (fnErr instanceof Error) {
+						throw fnErr;
+					} else {
+						throw new Error(fnErr);
+					}
 				}, err, msg);
 			});
 	}
diff --git a/test/promise.js b/test/promise.js
index 9fe4e34fd..51a758eb2 100644
--- a/test/promise.js
+++ b/test/promise.js
@@ -177,6 +177,30 @@ test('handle throws with string', function (t) {
 	});
 });
 
+test('handle throws with regex with string reject', function (t) {
+	ava(function (a) {
+		a.plan(1);
+
+		var promise = Promise.reject('abc');
+		return a.throws(promise, /abc/);
+	}).run().then(function (a) {
+		t.notOk(a.assertionError);
+		t.end();
+	});
+});
+
+test('handle throws with string with string reject', function (t) {
+	ava(function (a) {
+		a.plan(1);
+
+		var promise = Promise.reject('abc');
+		return a.throws(promise, 'abc');
+	}).run().then(function (a) {
+		t.notOk(a.assertionError);
+		t.end();
+	});
+});
+
 test('handle throws with false-positive promise', function (t) {
 	ava(function (a) {
 		a.plan(1);