diff --git a/tools/pretty_tox.sh b/tools/pretty_tox.sh
index 07c35a0..f3c88f3 100755
--- a/tools/pretty_tox.sh
+++ b/tools/pretty_tox.sh
@@ -3,4 +3,4 @@
 set -o pipefail
 
 TESTRARGS=$1
-python setup.py testr --slowest --testr-args="--subunit $TESTRARGS" | subunit2pyunit
+python setup.py testr --slowest --testr-args="--subunit $TESTRARGS" | $(dirname $0)/subunit-trace.py