diff --git a/pkgs/applications/virtualization/xen/packages.nix b/pkgs/applications/virtualization/xen/packages.nix
index f4bde18f3df..8f5262acb02 100644
--- a/pkgs/applications/virtualization/xen/packages.nix
+++ b/pkgs/applications/virtualization/xen/packages.nix
@@ -10,6 +10,8 @@ rec {
   xen_4_5-vanilla = callPackage ./4.5.nix {
     # At the very least included seabios and etherboot need gcc49,
     # so we have to build all of it with gcc49.
+    stdenv = overrideCC stdenv gcc49;
+
     meta = {
       description = "vanilla";
       longDescription = ''
@@ -58,6 +60,8 @@ rec {
   xen_4_8-vanilla = callPackage ./4.8.nix {
     # At the very least included seabios and etherboot need gcc49,
     # so we have to build all of it with gcc49.
+    stdenv = overrideCC stdenv gcc49;
+
     meta = {
       description = "vanilla";
       longDescription = ''