diff --git a/pkgs/build-support/vm/default.nix b/pkgs/build-support/vm/default.nix
index aa0592250403..1a54723726b1 100644
--- a/pkgs/build-support/vm/default.nix
+++ b/pkgs/build-support/vm/default.nix
@@ -98,6 +98,7 @@ rec {
       args=
       case $i in
         */cifs.ko)
+          args="CIFSMaxBufSize=4194304"
           ;;
       esac
       echo "loading module $(basename $i .ko)"