diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e585ab2..21a7f04 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -80,6 +80,10 @@ jobs:
       - uses: actions/checkout@v4
       - name: Install Rust
         uses: dtolnay/rust-toolchain@stable
+      - name: Bootstrap libsimplex on Windows
+        if: runner.os == 'Windows'
+        shell: powershell
+        run: ./scripts/bootstrap-simplex-windows.ps1
       # enable this ci template to run regardless of whether the lockfile is checked in or not
       - name: cargo generate-lockfile
         if: hashFiles('Cargo.lock') == ''
diff --git a/scripts/bootstrap-simplex-windows.ps1 b/scripts/bootstrap-simplex-windows.ps1
index c66e8f9..af3e71e 100644
--- a/scripts/bootstrap-simplex-windows.ps1
+++ b/scripts/bootstrap-simplex-windows.ps1
@@ -13,7 +13,11 @@ if (-not [Environment]::Is64BitOperatingSystem) {
 function Install-GhcupEnvironment {
     Write-Host "Installing missing GHCup/MSYS2 components..."
     $bootstrap = Invoke-WebRequest "https://www.haskell.org/ghcup/sh/bootstrap-haskell.ps1" -UseBasicParsing
-    & ([ScriptBlock]::Create($bootstrap.Content)) -Minimal -InBash -Msys2Env UCRT64 -DontWriteDesktopShortcuts
+    $bootstrapContent = $bootstrap.Content
+    if ($bootstrapContent -is [byte[]]) {
+        $bootstrapContent = [Text.Encoding]::UTF8.GetString($bootstrapContent)
+    }
+    & ([ScriptBlock]::Create([string] $bootstrapContent)) -Minimal -InBash -Msys2Env UCRT64 -DontWriteDesktopShortcuts
 }
 
 $Ghcup = Get-Command ghcup.exe -ErrorAction SilentlyContinue