diff --git a/tox.ini b/tox.ini
index 4a625f8..5e8d283 100644
--- a/tox.ini
+++ b/tox.ini
@@ -54,7 +54,7 @@
 setenv = OS_TEST_TIMEOUT=1200
 # The regex below is used to select heat api/scenario tests tagged as slow.
 commands =
-  bash tools/pretty_tox_serial.sh '(?=.*\[.*\bslow\b.*\])(^tempest\.(api|scenario)\.orchestration) {posargs}'
+  bash tools/pretty_tox.sh '(?=.*\[.*\bslow\b.*\])(^tempest\.(api|scenario)\.orchestration) {posargs}'
 
 [testenv:large-ops]
 sitepackages = True