diff --git a/lib/collection/query/update.js b/lib/collection/query/update.js
index aef9269..3782757 100644
--- a/lib/collection/query/update.js
+++ b/lib/collection/query/update.js
@@ -76,8 +76,10 @@ Query.prototype.promiseUpdate = function () {
   options.multi = true
   return new Promise(function (resolve, reject) {
     self.collection.update(self.criteria, self.document, options, function (err, results) {
-      if (err) reject(err)
-      else resolve(results)
+      if (err) return reject(err)
+      var result = results.result || results
+      if (result.nModified != null) return resolve(result.nModified)
+      resolve(result)
     })
   })
 }
diff --git a/lib/utils.js b/lib/utils.js
index 4d08173..71dab82 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -131,7 +131,7 @@ exports.updateify = function (constructor, fname) {
 exports.mapify = function (constructor) {
   constructor.prototype._transforms = null
   constructor.prototype.map = function (fn) {
-    assert('function', typeof fn)
+    assert.equal('function', typeof fn)
     var transforms = this._transforms = this._transforms || []
     transforms.push(fn)
     return this
diff --git a/test/search.js b/test/search.js
index ae831a3..9d65c49 100644
--- a/test/search.js
+++ b/test/search.js
@@ -116,7 +116,7 @@ describe('collection.find()', function () {
     return collection.count()
     .then(function (count) {
       assert(count)
-      assert('number', typeof count)
+      assert.equal('number', typeof count)
     })
   })
 
@@ -124,7 +124,7 @@ describe('collection.find()', function () {
     return collection.find().count()
     .then(function (count) {
       assert(count)
-      assert('number', typeof count)
+      assert.equal('number', typeof count)
     })
   })
 
@@ -132,7 +132,7 @@ describe('collection.find()', function () {
     collection.find().explain().count(function (err, count) {
       assert.ifError(err)
       assert(count)
-      assert('number', typeof count)
+      assert.equal('number', typeof count)
       done()
     })
   })
@@ -166,7 +166,7 @@ describe('collection.find()', function () {
       return collection.find().skip(null).then(function (docs) {
         assert.equal(length, docs.length)
         return collection.find().skip(1).then(function (docs) {
-          assert(length - 1, docs.length)
+          assert.equal(length - 1, docs.length)
         })
       })
     })
diff --git a/test/update.js b/test/update.js
index bc61120..44a60c4 100644
--- a/test/update.js
+++ b/test/update.js
@@ -6,7 +6,7 @@ describe('.find().update()', function () {
         asdf: 1
       }
     }).then(function (count) {
-      assert('number', typeof count)
+      assert.equal('number', typeof count)
       return collection.find()
     }).then(function (docs) {
       assert(docs.length > 1)
@@ -20,7 +20,7 @@ describe('.find().update()', function () {
     return collection.find().update('$set', {
       asdf: 2
     }).then(function (count) {
-      assert('number', typeof count)
+      assert.equal('number', typeof count)
       return collection.find()
     }).then(function (docs) {
       assert(docs.length > 1)
@@ -38,7 +38,7 @@ describe('.find().update()', function () {
     }).then(function (docs) {
       assert(docs.length > 1)
       assert(docs.every(function (doc) {
-        return doc.obj = true
+        return doc.obj === true
       }))
     })
   })