diff --git a/tox.ini b/tox.ini
index f7090273e..86ddf44bc 100644
--- a/tox.ini
+++ b/tox.ini
@@ -20,4 +20,4 @@ envlist =
 deps =
     -rrequirements.txt
 commands =
-    python -c 'import trezorlib'
+    python -m compileall trezorlib/