diff --git a/tests/dockerfile/simple/Dockerfile b/tests/dockerfile/simple/Dockerfile
index 492446360..a3e44b5c5 100644
--- a/tests/dockerfile/simple/Dockerfile
+++ b/tests/dockerfile/simple/Dockerfile
@@ -2,11 +2,11 @@ FROM python:3.10
 
 RUN pip install --no-cache notebook
 
-CMD "/bin/sh"
+CMD ["/bin/sh"]
 
 ADD sayhi.sh /usr/local/bin/sayhi.sh
 ADD verify verify
 
 ARG NB_UID
-ENV HOME /tmp
+ENV HOME=/tmp
 USER $NB_UID