diff --git a/Vagrantfile b/Vagrantfile
index 6cb571a88..73ae082e9 100644
--- a/Vagrantfile
+++ b/Vagrantfile
@@ -94,6 +94,9 @@ Vagrant.configure(2) do |config|
 
       # the script below will set up the steam-runtime docker containers
       sudo -u vagrant /home/vagrant/proton/vagrant-user-setup.sh
+
+      #ensure we use only the mingw-w64 that we built
+      apt-get remove -y '*mingw-w64*'
     SHELL
   end
 end
diff --git a/build-mingw-w64.sh b/build-mingw-w64.sh
index d4944d7f4..30076aa56 100755
--- a/build-mingw-w64.sh
+++ b/build-mingw-w64.sh
@@ -5,6 +5,8 @@ set -e
 if [ -z "$1" ]; then
     echo "Makes a local build of mingw-w64 in this directory and installs it to the given path."
     echo ""
+    echo "Note: Requires a system mingw-w64 to be present already, for us to bootstrap with."
+    echo ""
     echo "usage:"
     echo -e "\t$0 <installation path e.g. \$HOME/.local>"
     exit 1