diff --git a/nixos/modules/system/boot/binfmt.nix b/nixos/modules/system/boot/binfmt.nix
index 98db67e7c00..cceb02c1a73 100644
--- a/nixos/modules/system/boot/binfmt.nix
+++ b/nixos/modules/system/boot/binfmt.nix
@@ -134,11 +134,11 @@ let
       mask = ''\xff\xff\xff\xff'';
     };
     x86_64-windows = {
-      magicOrExtension = ".exe";
+      magicOrExtension = "exe";
       recognitionType = "extension";
     };
     i686-windows = {
-      magicOrExtension = ".exe";
+      magicOrExtension = "exe";
       recognitionType = "extension";
     };
   };