diff --git a/tox.ini b/tox.ini
index 31fb7bdef..2617feb99 100644
--- a/tox.ini
+++ b/tox.ini
@@ -15,7 +15,8 @@ envdir = {toxinidir}/.venv
 usedevelop = true
 
 [testenv:unittests]
-setenv = QT_QPA_PLATFORM_PLUGIN_PATH={envsitepackagesdir}/PyQt5/plugins/platforms
+# https://bitbucket.org/hpk42/tox/issue/246/
+setenv = QT_QPA_PLATFORM_PLUGIN_PATH={envdir}/lib/python3.4/PyQt5/plugins/platforms
 deps =
     py==1.4.27
     pytest==2.7.0