diff --git a/.gitignore b/.gitignore
index 68fb54467..4efcb9cb6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,3 +10,4 @@ distribute-*.egg
 distribute-*.tar.gz
 docs/_build
 docs/.docs-build-environment
+.tox/
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 000000000..848940599
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1,4 @@
+ecdsa>=0.9
+protobuf>=2.6.1
+mnemonic>=0.8
+hidapi>=0.7.99
diff --git a/tox.ini b/tox.ini
new file mode 100644
index 000000000..f7090273e
--- /dev/null
+++ b/tox.ini
@@ -0,0 +1,23 @@
+# To test against multiple python versions
+#
+#  1. Install those Python versions.
+#     On Ubuntu we suggest the deadsnakes PPA
+#     https://launchpad.net/~fkrull/+archive/ubuntu/deadsnakes
+#
+#  2. Install Tox (e.g. with pip)
+#         pip install Tox
+#
+#  3. Run Tox
+#         tox
+
+[tox]
+envlist =
+    py27,
+    py34,
+    py35,
+
+[testenv]
+deps =
+    -rrequirements.txt
+commands =
+    python -c 'import trezorlib'