diff --git a/test-requirements.txt b/test-requirements.txt
index 569d223c..4f986afb 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -12,6 +12,4 @@ testtools>=2.3.0 # MIT
 os-testr>=1.0.0 # Apache-2.0
 flake8>=3.3.0
 mock
-pytest==3.2.1
-pytest-mock
 responses>=0.8.1
diff --git a/tools/run-unit-tests.sh b/tools/run-unit-tests.sh
deleted file mode 100755
index feab07f9..00000000
--- a/tools/run-unit-tests.sh
+++ /dev/null
@@ -1,15 +0,0 @@
-#!/usr/bin/env bash
-
-# Script for passing regex filtering of unit tests to py.test conditionally.
-# Needed because tox currently doesn't support conditional logic like this.
-
-posargs=$@
-if [ ${#posargs} -ge 1 ]; then
-    py.test -vvv -s --ignore=hapi -k $1
-else
-    py.test -vvv -s --ignore=hapi
-fi
-TEST_STATUS=$?
-set -e
-
-exit $TEST_STATUS
diff --git a/tox.ini b/tox.ini
index a936684a..5254fe90 100644
--- a/tox.ini
+++ b/tox.ini
@@ -18,8 +18,13 @@ whitelist_externals =
     rm
 commands =
     find . -type f -name "*.pyc" -delete
-    python -V
-    {toxinidir}/tools/run-unit-tests.sh {posargs}
+    rm -Rf .testrepository/times.dbm
+
+[testenv:py35]
+commands =
+    {[testenv]commands}
+    stestr run {posargs}
+    stestr slowest
 
 [testenv:docs]
 deps = -r{toxinidir}/doc/requirements.txt