diff --git a/lib/index.js b/lib/index.js
index f06c7f8..9c05665 100755
--- a/lib/index.js
+++ b/lib/index.js
@@ -917,6 +917,20 @@ function StreamRedirect(to) {
     this.to = to;
 }
 
+/**
+ * Returns true if `x` is the end of stream marker.
+ *
+ * @id isNil
+ * @section Streams
+ * @name _.isNil(x)
+ * @param x - the object to test
+ * @api public
+ */
+
+_.isNil = function (x) {
+    return x === _.nil;
+};
+
 /**
  * Returns true if `x` is a Highland Stream.
  *
diff --git a/test/test.js b/test/test.js
index 1e0c3a7..9ebf8a6 100755
--- a/test/test.js
+++ b/test/test.js
@@ -324,6 +324,19 @@ exports.seq = function (test) {
     test.done();
 };
 
+exports.isNilTest = function (test) {
+    test.ok(_.isNil(_.nil));
+    test.ok(!_.isNil());
+    test.ok(!_.isNil(undefined));
+    test.ok(!_.isNil(null));
+    test.ok(!_.isNil(123));
+    test.ok(!_.isNil({}));
+    test.ok(!_.isNil([]));
+    test.ok(!_.isNil('foo'));
+    test.ok(!_.isNil(_()));
+    test.done();
+};
+
 exports.isStream = function (test) {
     test.ok(!_.isStream());
     test.ok(!_.isStream(undefined));