diff --git a/lib/messages/utils.js b/lib/messages/utils.js
index d1bd29e..eb3a975 100644
--- a/lib/messages/utils.js
+++ b/lib/messages/utils.js
@@ -7,12 +7,12 @@ var _ = bitcore.deps._;
 var utils;
 
 module.exports = utils = {
-  checkInventory: function(inventory) {
+  checkInventory: function(arg) {
     $.checkArgument(
-      _.isUndefined(inventory) ||
-        inventory.length === 0 ||
-        (!_.isUndefined(inventory[0].type) && !_.isUndefined(inventory[0].hash)),
-      'Inventory must be an array of inventory objects'
+      _.isUndefined(arg) ||
+        (Array.isArray(arg) && arg.length === 0) ||
+        (Array.isArray(arg) && !_.isUndefined(arg[0].type) && !_.isUndefined(arg[0].hash)),
+      'Argument is expected to be an array of inventory objects'
     );
   },
   checkFinished: function checkFinished(parser) {
diff --git a/test/messages/commands/index.js b/test/messages/commands/index.js
index ed28719..f4df5e6 100644
--- a/test/messages/commands/index.js
+++ b/test/messages/commands/index.js
@@ -70,6 +70,22 @@ describe('Command Messages', function() {
 
   });
 
+  describe('Inventory', function() {
+    it('should error if arg is not an array', function() {
+      (function() {
+        var message = messages.Inventory({});
+      }).should.throw('Argument is expected to be an array of inventory objects');
+    });
+    it('should not error if arg is an empty array', function() {
+      var message = messages.Inventory([]);
+    });
+    it('should error if arg is not an array of inventory objects', function() {
+      (function() {
+        var message = messages.Inventory([Number(0)]);
+      }).should.throw('Argument is expected to be an array of inventory objects');
+    });
+  });
+
   describe('Transaction', function() {
 
     it('should be able to pass a custom Transaction', function(done) {