diff --git a/index.js b/index.js
index 045577f..e951851 100644
--- a/index.js
+++ b/index.js
@@ -161,4 +161,6 @@ is.inRange = (x, range) => {
 	throw new TypeError(`Invalid range: ${util.inspect(range)}`);
 };
 
+is.infinite = x => x === Infinity || x === -Infinity;
+
 module.exports = is;
diff --git a/readme.md b/readme.md
index be284c4..66c1537 100644
--- a/readme.md
+++ b/readme.md
@@ -145,6 +145,9 @@ Check if `value` (number) is in the range of `0` to `upperBound`.
 is.inRange(3, 10);
 ```
 
+##### .infinite(value)
+
+Check if `value` is Infinity or -Infinity.
 
 ## FAQ
 
diff --git a/test.js b/test.js
index b4b50e6..3d57c60 100644
--- a/test.js
+++ b/test.js
@@ -358,3 +358,11 @@ test('is.inRange', t => {
 		m.inRange(0, [1, 2, 3]);
 	});
 });
+
+test('is.infinite', t => {
+	t.true(m.infinite(Infinity));
+	t.true(m.infinite(-Infinity));
+	t.false(m.infinite(NaN));
+	t.false(m.infinite(5));
+	t.false(m.infinite('hello world'));
+});