diff --git a/tests/dockerfile/binder-dir/binder/Dockerfile b/tests/dockerfile/binder-dir/binder/Dockerfile
index 4b721de4..989e2ec0 100644
--- a/tests/dockerfile/binder-dir/binder/Dockerfile
+++ b/tests/dockerfile/binder-dir/binder/Dockerfile
@@ -1,6 +1,12 @@
 FROM python:3.5
 
-ENTRYPOINT "/bin/sh"
+RUN pip install --no-cache notebook
+
+CMD "/bin/sh"
 
 ADD sayhi.sh /usr/local/bin/sayhi.sh
 ADD verify verify
+
+ARG NB_UID
+ENV HOME /tmp
+USER $NB_UID
diff --git a/tests/dockerfile/binder-dir/verify b/tests/dockerfile/binder-dir/verify
index 834ded63..03c14565 100755
--- a/tests/dockerfile/binder-dir/verify
+++ b/tests/dockerfile/binder-dir/verify
@@ -1,3 +1,3 @@
-#!/bin/sh
+#!/bin/bash
 set -euo pipefail
 /usr/local/bin/sayhi.sh
diff --git a/tests/dockerfile/simple/Dockerfile b/tests/dockerfile/simple/Dockerfile
index 4b721de4..989e2ec0 100644
--- a/tests/dockerfile/simple/Dockerfile
+++ b/tests/dockerfile/simple/Dockerfile
@@ -1,6 +1,12 @@
 FROM python:3.5
 
-ENTRYPOINT "/bin/sh"
+RUN pip install --no-cache notebook
+
+CMD "/bin/sh"
 
 ADD sayhi.sh /usr/local/bin/sayhi.sh
 ADD verify verify
+
+ARG NB_UID
+ENV HOME /tmp
+USER $NB_UID
diff --git a/tests/dockerfile/simple/verify b/tests/dockerfile/simple/verify
index 834ded63..03c14565 100755
--- a/tests/dockerfile/simple/verify
+++ b/tests/dockerfile/simple/verify
@@ -1,3 +1,3 @@
-#!/bin/sh
+#!/bin/bash
 set -euo pipefail
 /usr/local/bin/sayhi.sh