diff --git a/elements/puppet-stack-config/puppet-stack-config.pp b/elements/puppet-stack-config/puppet-stack-config.pp
index 5119aa8a9..56a31ed54 100644
--- a/elements/puppet-stack-config/puppet-stack-config.pp
+++ b/elements/puppet-stack-config/puppet-stack-config.pp
@@ -26,7 +26,11 @@ Exec<| title == 'glance-manage db_sync' |> { refreshonly => false }
 Exec<| title == 'nova-db-sync-api' |> { refreshonly => false }
 Exec<| title == 'nova-db-sync' |> { refreshonly => false }
 Exec<| title == 'nova-db-online-data-migrations' |> { refreshonly => false }
-Exec<| title == 'heat-dbsync' |> { refreshonly => false }
+Exec<| title == 'heat-dbsync' |> {
+  refreshonly => false,
+  # Heat database on the undercloud can be really big, db-sync take usually at least 10 min.
+  timeout     => 900,
+}
 Exec<| title == 'aodh-db-sync' |> { refreshonly => false }
 Exec<| title == 'ironic-dbsync' |> { refreshonly => false }
 Exec<| title == 'mistral-db-sync' |> { refreshonly => false }
diff --git a/releasenotes/notes/heat-dbsync-timeout-4301fb54b8711df5.yaml b/releasenotes/notes/heat-dbsync-timeout-4301fb54b8711df5.yaml
new file mode 100644
index 000000000..52b0ea337
--- /dev/null
+++ b/releasenotes/notes/heat-dbsync-timeout-4301fb54b8711df5.yaml
@@ -0,0 +1,8 @@
+---
+features:
+  - |
+    Increasing the heat db-sync from 5 to 15 minutes.
+    During an undercloud upgrade, the database can be very big and the
+    dbsync needs at least 10 minutes to run. So we override the Puppet
+    default value of 5 minutes to have a timeout of 15 minutes for
+    production deployments.