diff --git a/tox.ini b/tox.ini
index de4f1b7..befa991 100644
--- a/tox.ini
+++ b/tox.ini
@@ -135,6 +135,16 @@
     find . -type f -name "*.pyc" -delete
     tempest run --serial --regex '\[.*\bsmoke\b.*\]' {posargs}
 
+[testenv:slow-serial]
+envdir = .tox/tempest
+sitepackages = {[tempestenv]sitepackages}
+setenv = {[tempestenv]setenv}
+deps = {[tempestenv]deps}
+# The regex below is used to select the slow tagged tests to run serially:
+commands =
+    find . -type f -name "*.pyc" -delete
+    tempest run --serial --regex '\[.*\bslow\b.*\]' {posargs}
+
 [testenv:venv]
 deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}