diff --git a/nixos/modules/services/backup/borgbackup.nix b/nixos/modules/services/backup/borgbackup.nix
index 7ccb17073f6f..ea1d393c7b02 100644
--- a/nixos/modules/services/backup/borgbackup.nix
+++ b/nixos/modules/services/backup/borgbackup.nix
@@ -58,7 +58,7 @@ let
   '' + optionalString (cfg.prune.keep != { }) ''
     borg prune $extraArgs \
       ${mkKeepArgs cfg} \
-      ${optionalString (cfg.prune.prefix != null) "--glob-archives ${escapeShellArg "${cfg.prune.prefix}*"} \\"}
+      ${optionalString (cfg.prune.prefix != null) "--glob-archives ${escapeShellArg "${cfg.prune.prefix}*"}"} \
       $extraPruneArgs
     ${cfg.postPrune}
   '';