diff --git a/nixos/modules/services/networking/supplicant.nix b/nixos/modules/services/networking/supplicant.nix
index eb24130e519a..8df450a11c63 100644
--- a/nixos/modules/services/networking/supplicant.nix
+++ b/nixos/modules/services/networking/supplicant.nix
@@ -43,7 +43,7 @@ let
         path = [ pkgs.coreutils ];
 
         preStart = ''
-          ${optionalString (suppl.configFile.path!=null) ''
+          ${optionalString (suppl.configFile.path!=null && suppl.configFile.writable) ''
             (umask 077 && touch -a "${suppl.configFile.path}")
           ''}
           ${optionalString suppl.userControlled.enable ''