diff --git a/unixbuild.sh b/unixbuild.sh
index 91ea105..f5879be 100755
--- a/unixbuild.sh
+++ b/unixbuild.sh
@@ -39,6 +39,14 @@ if [ "$UPLATFORM" = "mac" ]; then
   export PATH="/opt/qt56sm/bin:$PATH"
 elif [ "$UPLATFORM" = "win32" ]; then
   # Install missing dependencies
+  curl -O -o /tmp/keyring.tar.xz http://repo.msys2.org/msys/x86_64/msys2-keyring-r21.b39fb11-1-any.pkg.tar.xz || exit 1
+  krsum=$(shasum -a 256 /tmp/keyring.tar.xz | cut -f1 -d' ')
+  krexpsum="f1cc152902fd6018868b64d015cab9bf547ff9789d8bd7c0d798fb2b22367b2b"
+  if [ "$krsum" != "$krexpsum" ]; then
+    echo "Keyring hash $krsum does not match $krexpsum"
+    exit 1
+  fi
+  pacman -U /tmp/keyring.tar.xz || exit 1
   pacman -Syu --ignore pacman --noconfirm || exit 1
   pacman -S --noconfirm --needed zip unzip curl perl mingw-w64-i686-toolchain mingw-w64-i686-cmake || exit 1