diff --git a/fedac/nixos/modules/kiosk.nix b/fedac/nixos/modules/kiosk.nix
index add9e1bf54..efcc365a5f 100644
--- a/fedac/nixos/modules/kiosk.nix
+++ b/fedac/nixos/modules/kiosk.nix
@@ -61,10 +61,10 @@ let
         >"$journal" 2>&1 || true
 
       if [ -f /tmp/ac-native-cage.log ]; then
-        cp /tmp/ac-native-cage.log "/mnt/logs/ac-native-cage-${stamp}.log" || true
+        cp /tmp/ac-native-cage.log "/mnt/logs/ac-native-cage-''${stamp}.log" || true
       fi
       if [ -f /tmp/cage-stderr.log ]; then
-        cp /tmp/cage-stderr.log "/mnt/logs/cage-stderr-${stamp}.log" || true
+        cp /tmp/cage-stderr.log "/mnt/logs/cage-stderr-''${stamp}.log" || true
       fi
       sync || true
     fi