diff --git a/tests/build_docker_images.py b/tests/build_docker_images.py
index 7bceda4d..60ceac10 100755
--- a/tests/build_docker_images.py
+++ b/tests/build_docker_images.py
@@ -50,7 +50,7 @@ RUN \
     useradd -s /bin/bash -m mitogen__slow_user && \
     chown -R root: ~mitogen__readonly_homedir && \
     { for i in `seq 1 21`; do useradd -s /bin/bash -m mitogen__user$i; done; } && \
-    { for i in `seq 1 21`; do echo mitogen__user$i:user$i_password | chpasswd; } && \
+    { for i in `seq 1 21`; do echo mitogen__user$i:user$i_password | chpasswd; done; } && \
     ( echo 'root:rootpassword' | chpasswd; ) && \
     ( echo 'mitogen__has_sudo:has_sudo_password' | chpasswd; ) && \
     ( echo 'mitogen__has_sudo_pubkey:has_sudo_pubkey_password' | chpasswd; ) && \
diff --git a/tox.ini b/tox.ini
index 70de05df..ae761121 100644
--- a/tox.ini
+++ b/tox.ini
@@ -8,7 +8,9 @@ deps =
     -r{toxinidir}/dev_requirements.txt
 
 commands =
-    {posargs:./test}
+    {posargs:bash run_tests}
+whitelist_externals =
+    bash
 
 [testenv:docs]
 basepython = python