diff --git a/pkgs/applications/virtualization/qemu/default.nix b/pkgs/applications/virtualization/qemu/default.nix
index e68cf7048b56..c20a2c53d600 100644
--- a/pkgs/applications/virtualization/qemu/default.nix
+++ b/pkgs/applications/virtualization/qemu/default.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchurl, fetchpatch, python3, zlib, pkg-config, glib, buildPackages
+{ lib, stdenv, fetchurl, fetchpatch, python3Packages, zlib, pkg-config, glib, buildPackages
 , perl, pixman, vde2, alsa-lib, texinfo, flex
 , bison, lzo, snappy, libaio, libtasn1, gnutls, nettle, curl, ninja, meson, sigtool
 , makeWrapper, runtimeShell, removeReferencesTo
@@ -51,7 +51,13 @@ stdenv.mkDerivation rec {
 
   depsBuildBuild = [ buildPackages.stdenv.cc ];
 
-  nativeBuildInputs = [ makeWrapper removeReferencesTo pkg-config flex bison meson ninja perl python3 python3.pkgs.sphinx python3.pkgs.sphinx-rtd-theme ]
+  nativeBuildInputs = [
+    makeWrapper removeReferencesTo
+    pkg-config flex bison meson ninja perl
+
+    # Don't change this to python3 and python3.pkgs.*, breaks cross-compilation
+    python3Packages.python python3Packages.sphinx python3Packages.sphinx-rtd-theme
+  ]
     ++ lib.optionals gtkSupport [ wrapGAppsHook ]
     ++ lib.optionals stdenv.isDarwin [ sigtool ];
 
@@ -143,7 +149,6 @@ stdenv.mkDerivation rec {
     # have our patches and will be subtly broken because of that.
     "--meson=meson"
     "--cross-prefix=${stdenv.cc.targetPrefix}"
-    "--cpu=${stdenv.hostPlatform.uname.processor}"
     (lib.enableFeature guestAgentSupport "guest-agent")
   ] ++ lib.optional numaSupport "--enable-numa"
     ++ lib.optional seccompSupport "--enable-seccomp"