diff --git a/modules/backup.nix b/modules/backup.nix
index 40c5425..a43dfa0 100644
--- a/modules/backup.nix
+++ b/modules/backup.nix
@@ -220,6 +220,8 @@ in
                 backupCleanupCommand = lib.strings.concatStringsSep "\n" instance.hooks.after_backup;
               } // lib.attrsets.optionalAttrs (instance.environmentFile) {
                 environmentFile = "/run/secrets/${instance.backend}/${name}/environmentfile";
+              } // lib.attrsets.optionalAttrs (builtins.length instance.excludePatterns > 0) {
+                exclude = instance.excludePatterns;
               };
             };
 
diff --git a/modules/nextcloud-server.nix b/modules/nextcloud-server.nix
index 17ccfbc..002fe7c 100644
--- a/modules/nextcloud-server.nix
+++ b/modules/nextcloud-server.nix
@@ -108,6 +108,7 @@ in
       sourceDirectories = [
         config.services.nextcloud.datadir
       ];
+      excludePatterns = [".rnd"];
     };
   };
 }