diff --git a/share/spack/templates/container/Dockerfile b/share/spack/templates/container/Dockerfile
index 2fad37affb..2f7aae901c 100644
--- a/share/spack/templates/container/Dockerfile
+++ b/share/spack/templates/container/Dockerfile
@@ -16,7 +16,8 @@ RUN {% if os_package_update %}{{ os_packages_build.update }} \
 
 # What we want to install and how we want to install it
 # is specified in a manifest file (spack.yaml)
-RUN mkdir {{ paths.environment }} \
+RUN mkdir -p {{ paths.environment }} && \
+set -o noclobber \
 {{ manifest }} > {{ paths.environment }}/spack.yaml
 
 # Install the software, remove unnecessary deps