diff --git a/backup/Dockerfile b/backup/Dockerfile
index 5839205..d275a30 100644
--- a/backup/Dockerfile
+++ b/backup/Dockerfile
@@ -4,10 +4,12 @@ RUN apk add postgresql-client
 RUN apk add dcron
 
 COPY pgsqlbackup.sh /usr/local/bin/pgsqlbackup.sh
+COPY drop_old_dumps.sh /usr/local/bin/drop_old_dumps.sh
 
 ENV DB_NAME="b2share"
 ENV DB_HOST="postgres"
 ENV DB_PORT="5432"
+ENV NUMBER_OF_DUMPS="30"
 
 # Create cron job
 COPY crontab /etc/cron.d/pgsqlbackup-cron
diff --git a/backup/crontab b/backup/crontab
index 5429279..2e173b7 100644
--- a/backup/crontab
+++ b/backup/crontab
@@ -1 +1,2 @@
 0 1 * * * /bin/sh /usr/local/bin/pgsqlbackup.sh 2>&1
+0 2 * * * /bin/sh /usr/local/bin/drop_old_dumps.sh 2>&1
diff --git a/backup/drop_old_dumps.sh b/backup/drop_old_dumps.sh
new file mode 100644
index 0000000..edda268
--- /dev/null
+++ b/backup/drop_old_dumps.sh
@@ -0,0 +1,6 @@
+#!/bin/bash
+#
+# Drop old database dumps.
+
+/usr/bin/find /usr/local/share/pgsql_dumps -type f -mtime +${NUMBER_OF_DUMPS} -delete
+
diff --git a/docker-compose.yml b/docker-compose.yml
index 6ae73ae..e18e3f3 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -112,6 +112,7 @@ services:
     #     environment:
     #         - "PGPASSWORD=${B2SHARE_POSTGRESQL_PASSWORD}"
     #         - "POSTGRES_USER=${B2SHARE_POSTGRESQL_USER}"
+    #         - "NUMBER_OF_DUMPS=30"
     #     volumes:
     #         - "${B2SHARE_DATADIR}/db_dump:/usr/local/share/pgsql_dumps"