diff --git a/Containers/postgresql/Dockerfile b/Containers/postgresql/Dockerfile
index 18b398cd..7446e337 100644
--- a/Containers/postgresql/Dockerfile
+++ b/Containers/postgresql/Dockerfile
@@ -1,13 +1,14 @@
-# From https://github.com/docker-library/postgres/blob/master/13/bullseye/Dockerfile
-FROM postgres:13-bullseye
+# From https://github.com/docker-library/postgres/blob/master/13/alpine/Dockerfile
+FROM postgres:13-alpine
 
+RUN apk add --update --no-cache bash openssl shadow
+
+# We need to use the same gid and uid as on old installations
 RUN set -ex; \
-    \
-    apt-get update; \
-    apt-get install -y --no-install-recommends \
-        openssl \
-    ; \
-    rm -rf /var/lib/apt/lists/*
+    deluser postgres; \
+    groupmod -g 9999 ping; \
+    addgroup -g 999 -S postgres; \
+    adduser -u 999 -S -D -G postgres -H -h /var/lib/postgresql -s /bin/sh postgres
 
 COPY start.sh /usr/bin/
 RUN chmod +x /usr/bin/start.sh