diff --git a/hosts/ha1/configuration.nix b/hosts/ha1/configuration.nix
index ce96519..7700339 100644
--- a/hosts/ha1/configuration.nix
+++ b/hosts/ha1/configuration.nix
@@ -87,6 +87,7 @@
       "--keep-monthly 6"
       "--keep-within 1d"
     ];
+    extraOptions = [ "--retry-lock=5m" ];
   };
 
   # Open ports in the firewall.
diff --git a/hosts/monitoring01/configuration.nix b/hosts/monitoring01/configuration.nix
index a437e81..7f87ef7 100644
--- a/hosts/monitoring01/configuration.nix
+++ b/hosts/monitoring01/configuration.nix
@@ -83,6 +83,7 @@
       "--keep-monthly 6"
       "--keep-within 1d"
     ];
+    extraOptions = [ "--retry-lock=5m" ];
   };
 
   services.restic.backups.grafana-db = {
@@ -100,6 +101,7 @@
       "--keep-monthly 6"
       "--keep-within 1d"
     ];
+    extraOptions = [ "--retry-lock=5m" ];
   };
 
   # Open ports in the firewall.