diff --git a/.github/scripts/get_win_deps.ps1 b/.github/scripts/get_win_deps.ps1
new file mode 100644
index 00000000..b947ad5c
--- /dev/null
+++ b/.github/scripts/get_win_deps.ps1
@@ -0,0 +1,23 @@
+function getlibrary ([string] $URI, [string] $filename, [string] $hash, [string] $destdir) {
+	$wc = New-Object Net.WebClient
+	[string] $downloadhash = $null
+	try {
+		$wc.DownloadFile($URI, $filename)
+		$downloadhash = $(Get-FileHash $filename -Algorithm SHA256).Hash
+	} catch {
+		Write-Host "${filename}: failed to download"
+		exit 1
+	}
+	if ($hash -ne $downloadhash) {
+		Write-Host "${filename}: SHA256 mismatch ($downloadhash)"
+		exit 1
+	}
+	Expand-Archive -DestinationPath $destdir $filename
+}
+
+getlibrary 'https://www.zlib.net/zlib1213.zip' 'zlib.zip' 'd233fca7cf68db4c16dc5287af61f3cd01ab62495224c66639ca3da537701e42' .
+getlibrary 'https://download.sourceforge.net/libpng/lpng1637.zip' 'libpng.zip'  '3b4b1cbd0bae6822f749d39b1ccadd6297f05e2b85a83dd2ce6ecd7d09eabdf2' .
+getlibrary 'https://github.com/lexxmark/winflexbison/releases/download/v2.5.24/win_flex_bison-2.5.24.zip' 'winflexbison.zip'  '39c6086ce211d5415500acc5ed2d8939861ca1696aee48909c7f6daf5122b505' install_dir
+
+Move-Item zlib-1.2.13 zlib
+Move-Item lpng1637 libpng
diff --git a/.github/workflows/create-release-artifacts.yaml b/.github/workflows/create-release-artifacts.yaml
index 99f3c523..8d8ff0e2 100644
--- a/.github/workflows/create-release-artifacts.yaml
+++ b/.github/workflows/create-release-artifacts.yaml
@@ -25,31 +25,8 @@ jobs:
           VERSION="${{ github.ref_name }}"
           echo "version=${VERSION#v}" >> $GITHUB_ENV
       - uses: actions/checkout@v2
-      - name: Get zlib, libpng and bison
-        run: | # TODO: use an array; remember to update the versions being downloaded, *and* the paths being extracted! (`Move-Item`)
-          $wc = New-Object System.Net.WebClient
-          $wc.DownloadFile('https://www.zlib.net/zlib1213.zip', 'zlib.zip')
-          $hash = (Get-FileHash "zlib.zip" -Algorithm SHA256).Hash
-          if ($hash -ne 'd233fca7cf68db4c16dc5287af61f3cd01ab62495224c66639ca3da537701e42') {
-            Write-Host "zlib SHA256 mismatch! ($hash)"
-            exit 1
-          }
-          $wc.DownloadFile('https://download.sourceforge.net/libpng/lpng1637.zip', 'libpng.zip')
-          $hash = (Get-FileHash "libpng.zip" -Algorithm SHA256).Hash
-          if ($hash -ne '3b4b1cbd0bae6822f749d39b1ccadd6297f05e2b85a83dd2ce6ecd7d09eabdf2') {
-            Write-Host "libpng SHA256 mismatch! ($hash)"
-            exit 1
-          }
-          $wc.DownloadFile('https://github.com/lexxmark/winflexbison/releases/download/v2.5.24/win_flex_bison-2.5.24.zip', 'winflexbison.zip')
-          $hash = (Get-FileHash "winflexbison.zip" -Algorithm SHA256).Hash
-          if ($hash -ne '39c6086ce211d5415500acc5ed2d8939861ca1696aee48909c7f6daf5122b505') {
-            Write-Host "bison SHA256 mismatch! ($hash)"
-          }
-          Expand-Archive -DestinationPath .           "zlib.zip"
-          Expand-Archive -DestinationPath .           "libpng.zip"
-          Expand-Archive -DestinationPath install_dir "winflexbison.zip"
-          Move-Item zlib-1.2.13 zlib
-          Move-Item lpng1637 libpng
+      - name: Install deps
+        run: .github/scripts/get_win_deps.ps1
       - uses: actions/cache@v3
         id: cache
         with:
diff --git a/.github/workflows/testing.yml b/.github/workflows/testing.yml
index 68bf997d..2b40cd5f 100644
--- a/.github/workflows/testing.yml
+++ b/.github/workflows/testing.yml
@@ -76,31 +76,8 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v2
-      - name: Get zlib, libpng and bison
-        run: | # TODO: use an array; remember to update the versions being downloaded, *and* the paths being extracted! (`Move-Item`)
-          $wc = New-Object System.Net.WebClient
-          $wc.DownloadFile('https://www.zlib.net/zlib1213.zip', 'zlib.zip')
-          $hash = (Get-FileHash "zlib.zip" -Algorithm SHA256).Hash
-          if ($hash -ne 'd233fca7cf68db4c16dc5287af61f3cd01ab62495224c66639ca3da537701e42') {
-            Write-Host "zlib SHA256 mismatch! ($hash)"
-            exit 1
-          }
-          $wc.DownloadFile('https://download.sourceforge.net/libpng/lpng1637.zip', 'libpng.zip')
-          $hash = (Get-FileHash "libpng.zip" -Algorithm SHA256).Hash
-          if ($hash -ne '3b4b1cbd0bae6822f749d39b1ccadd6297f05e2b85a83dd2ce6ecd7d09eabdf2') {
-            Write-Host "libpng SHA256 mismatch! ($hash)"
-            exit 1
-          }
-          $wc.DownloadFile('https://github.com/lexxmark/winflexbison/releases/download/v2.5.24/win_flex_bison-2.5.24.zip', 'winflexbison.zip')
-          $hash = (Get-FileHash "winflexbison.zip" -Algorithm SHA256).Hash
-          if ($hash -ne '39c6086ce211d5415500acc5ed2d8939861ca1696aee48909c7f6daf5122b505') {
-            Write-Host "bison SHA256 mismatch! ($hash)"
-          }
-          Expand-Archive -DestinationPath .           "zlib.zip"
-          Expand-Archive -DestinationPath .           "libpng.zip"
-          Expand-Archive -DestinationPath install_dir "winflexbison.zip"
-          Move-Item zlib-1.2.13 zlib
-          Move-Item lpng1637 libpng
+      - name: Install deps
+        run: .github/scripts/get_win_deps.ps1
       - uses: actions/cache@v3
         id: cache
         with: