diff --git a/bin/ncp-update-nc b/bin/ncp-update-nc
index 2bec0aa5e..50f6379bf 100755
--- a/bin/ncp-update-nc
+++ b/bin/ncp-update-nc
@@ -234,6 +234,9 @@ fi
 rm -rf /var/www/nextcloud/apps/previewgenerator
 ln -snf "${NCPREV}" /var/www/nextcloud/apps/previewgenerator
 
+# refresh completions
+ncc _completion -g --shell-type bash -p ncc | sed 's|/var/www/nextcloud/occ|ncc|g' > /usr/share/bash-completion/completions/ncp
+
 # done
 ####################
 mkdir -p  "$DATADIR"/ncp-update-backups
diff --git a/bin/ncp/CONFIG/nc-init.sh b/bin/ncp/CONFIG/nc-init.sh
index 9acfdbb30..0df7c3c84 100644
--- a/bin/ncp/CONFIG/nc-init.sh
+++ b/bin/ncp/CONFIG/nc-init.sh
@@ -181,6 +181,12 @@ EOF
   ncc config:system:set overwrite.cli.url --value="https://nextcloudpi/"
   ncc config:system:set trusted_domains "${TRUSTED_DOMAINS[nc_domain]}" --value="nextcloudpi"
 
+  # bash completion for ncc
+  apt_install bash-completion
+  ncc _completion -g --shell-type bash -p ncc | sed 's|/var/www/nextcloud/occ|ncc|g' > /usr/share/bash-completion/completions/ncp
+  echo ". /etc/bash_completion" >> /etc/bash.bashrc
+  echo ". /usr/share/bash-completion/completions/ncp" >> /etc/bash.bashrc
+
   # TODO temporary workaround for https://github.com/nextcloud/server/pull/13358
   ncc -n db:convert-filecache-bigint
   ncc db:add-missing-indices
diff --git a/changelog.md b/changelog.md
index 7e60de1fa..ce52e0418 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,7 @@
 
-[v1.39.16](https://github.com/nextcloud/nextcloudpi/commit/e6ebc3d) (2021-09-27) nc-https: proto logic was inverted fix
+[v1.39.17](https://github.com/nextcloud/nextcloudpi/commit/520f062) (2021-09-29) add bash completion to ncc
+
+[v1.39.16](https://github.com/nextcloud/nextcloudpi/commit/2be666b) (2021-09-27) nc-https: proto logic was inverted fix
 
 [v1.39.15](https://github.com/nextcloud/nextcloudpi/commit/b067844) (2021-09-27) add get_ip function
 
diff --git a/ncp.sh b/ncp.sh
index 8fff524de..26bc0fe41 100644
--- a/ncp.sh
+++ b/ncp.sh
@@ -34,7 +34,7 @@ install()
   # add the ncc shortcut
   cat > /usr/local/bin/ncc <<'EOF'
 #!/bin/bash
-sudo -u www-data php /var/www/nextcloud/occ "$@"
+sudo -E -u www-data php /var/www/nextcloud/occ "$@"
 EOF
   chmod +x /usr/local/bin/ncc
 
diff --git a/updates/1.40.0.sh b/updates/1.40.0.sh
index 139934ed3..2741ab7bb 100644
--- a/updates/1.40.0.sh
+++ b/updates/1.40.0.sh
@@ -36,6 +36,19 @@ EOF
 # fix issue with reverse proxy infinite redirections
 run_app nc-httpsonly
 
+# bash completion for `ncc`
+if ! [[ -f /usr/share/bash-completion/completions/ncp ]]; then
+  apt_install bash-completion
+  ncc _completion -g --shell-type bash -p ncc | sed 's|/var/www/nextcloud/occ|ncc|g' > /usr/share/bash-completion/completions/ncp
+  echo ". /etc/bash_completion" >> /etc/bash.bashrc
+  echo ". /usr/share/bash-completion/completions/ncp" >> /etc/bash.bashrc
+  cat > /usr/local/bin/ncc <<'EOF'
+#!/bin/bash
+sudo -E -u www-data php /var/www/nextcloud/occ "$@"
+EOF
+  chmod +x /usr/local/bin/ncc
+fi
+
 # docker images only
 [[ -f /.docker-image ]] && {
   :