diff --git a/kube/values/base/config.yaml b/kube/values/base/config.yaml
index 81d00e96a0ce15943be4165cdf289723fee72e5d..c7b3949765e6cf00ac0d8d29fe1e688d0727109e 100644
--- a/kube/values/base/config.yaml
+++ b/kube/values/base/config.yaml
@@ -186,23 +186,23 @@ outpostConfig: |-
           elif notebook_type == "url" and notebook:
               spawner.default_url = notebook
       if spawner.user_options["option"] in ["repo2docker", "custom"]:
-          # spawner.cmd = ["/bin/sh", "-c"]
           spawner.cmd = [
+              "bash", "-c",
               '''
               # Get the current jupyterhub-singleuser version
               version=$(jupyterhub-singleuser --version || echo "0.0.0")
-              
+
               # Set the desired version range
               min_version="4.0.0"
               max_version="5.0.0"
               target_version="4.1.6"
-              
+
               # Function to check if the version is in range
               in_range() {
                   [ "$(printf '%s\n' "$min_version" "$1" | sort -V | head -n1)" = "$min_version" ] && \
                   [ "$(printf '%s\n' "$1" "$max_version" | sort -V | head -n1)" = "$1" ]
               }
-              
+
               # Check if the current version is within the range
               if ! in_range "$version"; then
                   echo "Installing jupyterhub-singleuser $target_version as version $version is not within $min_version - $max_version."
@@ -210,7 +210,7 @@ outpostConfig: |-
               else
                   echo "jupyterhub-singleuser $version is within the required version range."
               fi
-              
+
               # Start the jupyterhub-singleuser
               command -v start-singleuser.sh >/dev/null 2>&1 && exec start-singleuser.sh || exec jupyterhub-singleuser
               '''