diff --git a/12/alpine/Dockerfile b/12/alpine/Dockerfile
index c2586bec7f..ad99c63a2b 100644
--- a/12/alpine/Dockerfile
+++ b/12/alpine/Dockerfile
@@ -5,7 +5,7 @@ FROM alpine:3.11
 # https://git.alpinelinux.org/aports/tree/main/postgresql/postgresql.pre-install?h=3.11-stable
 RUN set -eux; \
 	addgroup -g 70 -S postgres; \
-	adduser -u 70 -S -D -G postgres -H -h /var/lib/postgresql postgres; \
+	adduser -u 70 -S -D -G postgres -H -h /var/lib/postgresql -s /bin/sh postgres; \
 	mkdir -p /var/lib/postgresql; \
 	chown -R postgres:postgres /var/lib/postgresql
 
diff --git a/Dockerfile-alpine.template b/Dockerfile-alpine.template
index e1b4a6f947..7819ce02a6 100644
--- a/Dockerfile-alpine.template
+++ b/Dockerfile-alpine.template
@@ -5,7 +5,7 @@ FROM alpine:%%ALPINE-VERSION%%
 # https://git.alpinelinux.org/aports/tree/main/postgresql/postgresql.pre-install?h=3.11-stable
 RUN set -eux; \
 	addgroup -g 70 -S postgres; \
-	adduser -u 70 -S -D -G postgres -H -h /var/lib/postgresql postgres; \
+	adduser -u 70 -S -D -G postgres -H -h /var/lib/postgresql -s /bin/sh postgres; \
 	mkdir -p /var/lib/postgresql; \
 	chown -R postgres:postgres /var/lib/postgresql