diff --git a/mongoengine/fields.py b/mongoengine/fields.py
index edf6515b..9d01d81c 100644
--- a/mongoengine/fields.py
+++ b/mongoengine/fields.py
@@ -8,6 +8,8 @@ import uuid
 import warnings
 from operator import itemgetter
 
+import six
+
 try:
     import dateutil
 except ImportError:
@@ -260,14 +262,14 @@ class FloatField(BaseField):
         return value
 
     def validate(self, value):
-        if isinstance(value, (int, long)):
+        if isinstance(value, six.integer_types):
             try:
                 value = float(value)
             except OverflowError:
                 self.error('The value is too large to be converted to float')
 
         if not isinstance(value, float):
-            self.error('FloatField only accepts float, int and long values')
+            self.error('FloatField only accepts float and integer values')
 
         if self.min_value is not None and value < self.min_value:
             self.error('Float value is too small')
diff --git a/requirements.txt b/requirements.txt
index 03935868..b6a5b06c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,3 @@
-pymongo>=2.7.1
 nose
+pymongo>=2.7.1
+six==1.10.0
diff --git a/setup.py b/setup.py
index 6aa924c8..e34d834a 100644
--- a/setup.py
+++ b/setup.py
@@ -78,7 +78,7 @@ setup(name='mongoengine',
       long_description=LONG_DESCRIPTION,
       platforms=['any'],
       classifiers=CLASSIFIERS,
-      install_requires=['pymongo>=2.7.1'],
+      install_requires=['pymongo>=2.7.1', 'six'],
       test_suite='nose.collector',
       **extra_opts
 )
diff --git a/tests/fields/fields.py b/tests/fields/fields.py
index 3b048094..1c1f49ad 100644
--- a/tests/fields/fields.py
+++ b/tests/fields/fields.py
@@ -1,5 +1,7 @@
 # -*- coding: utf-8 -*-
 import sys
+
+import six
 from nose.plugins.skip import SkipTest
 
 sys.path[0:0] = [""]
@@ -420,8 +422,9 @@ class FieldTest(unittest.TestCase):
 
         big_person = BigPerson()
 
-        big_person.height = 1L
-        big_person.validate()
+        for value, value_type in enumerate(six.integer_types):
+            big_person.height = value_type(value)
+            big_person.validate()
 
         big_person.height = 2 ** 500
         big_person.validate()