diff --git a/tox.ini b/tox.ini
index 7e70682e7..c576bed72 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,7 +5,6 @@ envlist = py34,py27,pep8
 setenv =
     VIRTUAL_ENV={envdir}
     OS_TEST_TIMEOUT=30
-    PN_TRACE_FRM=1
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 commands = python setup.py testr --slowest --testr-args='{posargs}'