diff --git a/.gitignore b/.gitignore
index efee854d..18026d60 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,4 +11,5 @@ build/
 .idea/
 *.swp
 .DS_Store
-python_env
\ No newline at end of file
+python_env
+.ropeproject/
diff --git a/requirements-dev.txt b/requirements-dev.txt
index e2f379a5..28aaec60 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -8,4 +8,4 @@ freezegun
 flask
 boto3>=1.4.4
 botocore>=1.5.77
-six
+six>=1.9
diff --git a/setup.py b/setup.py
index 07cf9838..b6de5686 100755
--- a/setup.py
+++ b/setup.py
@@ -10,11 +10,11 @@ install_requires = [
     "requests>=2.5",
     "xmltodict",
     "dicttoxml",
-    "six",
+    "six>1.9",
     "werkzeug",
     "pyaml",
     "pytz",
-    "python-dateutil",
+    "python-dateutil<3.0.0,>=2.1",
     "mock",
 ]