diff --git a/getdeck/sources/tooler.py b/getdeck/sources/tooler.py
index be4b566..f3778dd 100644
--- a/getdeck/sources/tooler.py
+++ b/getdeck/sources/tooler.py
@@ -87,8 +87,8 @@ def build_user_container(config: ClientConfiguration):
         user_group_add = "RUN addgroup -S tooler && adduser -S tooler -G tooler"
     else:
         user_group_add = (
-            "RUN cat /etc/group | grep ${GROUP_ID} || addgroup -g ${GROUP_ID} -S tooler && "
-            "cat /etc/passwd | grep ${USER_ID} || adduser -u ${USER_ID} -S tooler -G tooler"
+            "RUN getent group ${GROUP_ID} || addgroup -g ${GROUP_ID} -S tooler && "
+            "getent passwd ${USER_ID} || adduser -u ${USER_ID} -S tooler -G $(getent group ${GROUP_ID} | cut -d: -f1)"
         )
 
     Dockerfile = io.BytesIO(