diff --git a/dev-requirements.txt b/dev-requirements.txt
new file mode 100644
index 0000000..84c7697
--- /dev/null
+++ b/dev-requirements.txt
@@ -0,0 +1 @@
+tox>=1.4,<1.5
diff --git a/requirements.txt b/requirements.txt
deleted file mode 100644
index 75112a2..0000000
--- a/requirements.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-pycrypto
-tox
diff --git a/tox.ini b/tox.ini
index 6cb8001..e2a8dcf 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,5 +2,5 @@
 envlist = py25,py26,py27
 
 [testenv]
-commands = pip install --use-mirrors -q -r requirements.txt
+commands = pip install --use-mirrors -q -r dev-requirements.txt
            python test.py