diff --git a/Dockerfile-alpine b/Dockerfile-alpine
index a5db5f9..fe53043 100644
--- a/Dockerfile-alpine
+++ b/Dockerfile-alpine
@@ -6,21 +6,21 @@ RUN set -x \
 	&& chmod a+x /usr/local/bin/go-cron \
 	&& apk del ca-certificates
 
-ENV POSTGRES_DB **None**
-ENV POSTGRES_DB_FILE **None**
-ENV POSTGRES_HOST **None**
-ENV POSTGRES_PORT 5432
-ENV POSTGRES_USER **None**
-ENV POSTGRES_USER_FILE **None**
-ENV POSTGRES_PASSWORD **None**
-ENV POSTGRES_PASSWORD_FILE **None**
-ENV POSTGRES_EXTRA_OPTS '-Z9'
-ENV SCHEDULE '@daily'
-ENV BACKUP_DIR '/backups'
-ENV BACKUP_KEEP_DAYS 7
-ENV BACKUP_KEEP_WEEKS 4
-ENV BACKUP_KEEP_MONTHS 6
-ENV HEALTHCHECK_PORT 8080
+ENV POSTGRES_DB **None** \
+    POSTGRES_DB_FILE **None** \
+    POSTGRES_HOST **None** \
+    POSTGRES_PORT 5432 \
+    POSTGRES_USER **None** \
+    POSTGRES_USER_FILE **None** \
+    POSTGRES_PASSWORD **None** \
+    POSTGRES_PASSWORD_FILE **None** \
+    POSTGRES_EXTRA_OPTS '-Z9' \
+    SCHEDULE '@daily' \
+    BACKUP_DIR '/backups' \
+    BACKUP_KEEP_DAYS 7 \
+    BACKUP_KEEP_WEEKS 4 \
+    BACKUP_KEEP_MONTHS 6 \
+    HEALTHCHECK_PORT 8080
 
 COPY backup.sh /backup.sh
 
diff --git a/Dockerfile-debian b/Dockerfile-debian
index 9cccad5..af8a183 100644
--- a/Dockerfile-debian
+++ b/Dockerfile-debian
@@ -6,21 +6,21 @@ RUN set -x \
 	&& chmod a+x /usr/local/bin/go-cron \
 	&& apt-get purge -y --auto-remove ca-certificates && apt-get clean
 
-ENV POSTGRES_DB **None**
-ENV POSTGRES_DB_FILE **None**
-ENV POSTGRES_HOST **None**
-ENV POSTGRES_PORT 5432
-ENV POSTGRES_USER **None**
-ENV POSTGRES_USER_FILE **None**
-ENV POSTGRES_PASSWORD **None**
-ENV POSTGRES_PASSWORD_FILE **None**
-ENV POSTGRES_EXTRA_OPTS '-Z9'
-ENV SCHEDULE '@daily'
-ENV BACKUP_DIR '/backups'
-ENV BACKUP_KEEP_DAYS 7
-ENV BACKUP_KEEP_WEEKS 4
-ENV BACKUP_KEEP_MONTHS 6
-ENV HEALTHCHECK_PORT 8080
+ENV POSTGRES_DB **None** \
+    POSTGRES_DB_FILE **None** \
+    POSTGRES_HOST **None** \
+    POSTGRES_PORT 5432 \
+    POSTGRES_USER **None** \
+    POSTGRES_USER_FILE **None** \
+    POSTGRES_PASSWORD **None** \
+    POSTGRES_PASSWORD_FILE **None** \
+    POSTGRES_EXTRA_OPTS '-Z9' \
+    SCHEDULE '@daily' \
+    BACKUP_DIR '/backups' \
+    BACKUP_KEEP_DAYS 7 \
+    BACKUP_KEEP_WEEKS 4 \
+    BACKUP_KEEP_MONTHS 6 \
+    HEALTHCHECK_PORT 8080
 
 COPY backup.sh /backup.sh