diff --git a/lib/model.js b/lib/model.js
index 4a5af8f..1d6346c 100644
--- a/lib/model.js
+++ b/lib/model.js
@@ -328,6 +328,18 @@ comparisonFunctions.$ne = function (a, b) {
   return !areThingsEqual(a, b);
 };
 
+comparisonFunctions.$in = function (a, b) {
+  var i;
+
+  if (!util.isArray(b)) { throw "$in operator called with a non-array"; }
+
+  for (i = 0; i < b.length; i += 1) {
+    if (areThingsEqual(a, b[i])) { return true; }
+  }
+
+  return false;
+};
+
 
 /**
  * Match any of the subqueries
diff --git a/test/model.test.js b/test/model.test.js
index 4259d25..720a572 100644
--- a/test/model.test.js
+++ b/test/model.test.js
@@ -459,7 +459,7 @@ describe('Model', function () {
 
 
     // General behaviour is tested in the block about $lt. Here we just test operators work
-    describe('Other comparison operators: $lte, $gt, $gte, $ne', function () {
+    describe('Other comparison operators: $lte, $gt, $gte, $ne, $in', function () {
 
       it('$lte', function () {
         model.match({ a: 5 }, { a: { $lte: 6 } }).should.equal(true);
@@ -485,6 +485,16 @@ describe('Model', function () {
         model.match({ a: 5 }, { b: { $ne: 5 } }).should.equal(true);
       });
 
+      it('$in', function () {
+        model.match({ a: 5 }, { a: { $in: [6, 8, 9] } }).should.equal(false);
+        model.match({ a: 6 }, { a: { $in: [6, 8, 9] } }).should.equal(true);
+        model.match({ a: 7 }, { a: { $in: [6, 8, 9] } }).should.equal(false);
+        model.match({ a: 8 }, { a: { $in: [6, 8, 9] } }).should.equal(true);
+        model.match({ a: 9 }, { a: { $in: [6, 8, 9] } }).should.equal(true);
+
+        (function () { model.match({ a: 5 }, { a: { $in: 5 } }); }).should.throw();
+      });
+
     });