diff --git a/modules/installer/cd-dvd/iso-image.nix b/modules/installer/cd-dvd/iso-image.nix
index 4a3dc87b4c76..96a4d411d0b9 100644
--- a/modules/installer/cd-dvd/iso-image.nix
+++ b/modules/installer/cd-dvd/iso-image.nix
@@ -148,7 +148,7 @@ let
     '';
 
   targetArch = if pkgs.stdenv.isi686 then
-    "IA32"
+    "ia32"
   else if pkgs.stdenv.isx86_64 then
     "x64"
   else