diff --git a/tools/pretty_tox.sh b/tools/pretty_tox.sh
index dcab82c7..c5a62e3a 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" | subunit-trace -f
\ No newline at end of file
+python setup.py testr --slowest --testr-args="--subunit $TESTRARGS" | python $(which subunit-trace) -f