diff --git a/Dockerfile.template b/Dockerfile.template
index a754e4786b..f891d7a82b 100644
--- a/Dockerfile.template
+++ b/Dockerfile.template
@@ -1,8 +1,8 @@
 # vim:set ft=dockerfile:
 FROM debian:jessie
 
-# add our user and group first to make sure their IDs get assigned consistently, regardless of whatever dependencies get added
-RUN groupadd -r postgres && useradd -r -g postgres postgres
+# explicitly set user/group IDs
+RUN groupadd -r postgres --gid=999 && useradd -r -g postgres --uid=999 postgres
 
 # grab gosu for easy step-down from root
 RUN gpg --keyserver pool.sks-keyservers.net --recv-keys B42F6819007F00F88E364FD4036A9C25BF357DD4