diff --git a/nixos/tests/installer.nix b/nixos/tests/installer.nix
index 782df7eab2a2..9149b1bff02f 100644
--- a/nixos/tests/installer.nix
+++ b/nixos/tests/installer.nix
@@ -98,6 +98,7 @@ let
       # FIXME: OVMF doesn't boot from virtio http://www.mail-archive.com/edk2-devel@lists.sourceforge.net/msg01501.html
       iface = if useEFI || grubVersion == 1 then "scsi" else "virtio";
       qemuFlags =
+        (if iso.system == "x86_64-linux" then "-m 512 " else "-m 384 ") +
         (optionalString (iso.system == "x86_64-linux") "-cpu kvm64 ") +
         (optionalString useEFI ''-L ${efiBios} -hda ''${\(Cwd::abs_path('harddisk'))} '');
       hdFlags = optionalString (!useEFI)