diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index bd63af0e..3b36deb5 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -702,7 +702,7 @@ jobs:
           export MSI_FILENAME="${GITHUB_WORKSPACE}/gam-${GAMVERSION}-windows-${GAM_ARCHIVE_ARCH}.msi"
           # auto-generate a lib.wxs based on the files PyInstaller created for the lib/ directory
           /c/Program\ Files\ \(x86\)/WiX\ Toolset\ v3.14/bin/heat.exe dir "${gampath}/lib" -ke -srd -cg Lib -gg -dr lib -directoryid lib -out lib-fixme.wxs
-          sed 's/Guid=\".*\"/Guid="*"/g' lib-fixme.wxs > lib.wxs
+          $python tools/gen-wix-xml-filelist.py lib.wxs
           echo "-- begin lib.wxs --"
           cat lib.wxs
           echo "-- end lib.wxs --"
diff --git a/src/tools/gen-wix-xml-filelist.py b/src/tools/gen-wix-xml-filelist.py
index 8702ee63..e7c9474f 100644
--- a/src/tools/gen-wix-xml-filelist.py
+++ b/src/tools/gen-wix-xml-filelist.py
@@ -1,58 +1,23 @@
-import os
-import sys
 import uuid
+from lxml import etree
+import sys
 
-source_dir = sys.argv[1]
-template_file = sys.argv[2]
-target_file = sys.argv[3]
+# Hacky solution to create a Guid for all files
+# so Wix is happy and Guid is stable every time.
+# uuid5 is used for the Guid and the input is the
+# source filename so the Guid will be the same
+# every time as long as the source file name is
+# the same.
 
-existing_components = {
-    'gam.exe': '''      <Component Id="gam_exe" Guid="d046ea24-c9f8-40ca-84db-70b0119933ff">
-        <File Name="gam.exe" KeyPath="yes" />
-        <Environment Id="PATH" Name="PATH" Value="[INSTALLFOLDER]" Permanent="yes" Part="last" Action="set" System="yes" />
-      </Component>
-''',
-    'LICENSE': '''      <Component Id="license" Guid="c76864c5-d005-44d5-bb7c-a27e5923792d">
-        <File Name="LICENSE" KeyPath="yes" />
-      </Component>
-''',
-    'gam-setup.bat': '''      <Component Id="gam_setup_bat" Guid="5e6bbacb-d86f-4d80-a10b-89b81ee63fcb">
-        <File Name="gam-setup.bat" KeyPath="yes" />
-      </Component>
-''',
-    'GamCommands.txt': '''      <Component Id="GamCommands_txt" Guid="a2dca862-b222-469e-a637-95ea2a1c53e7">
-        <File Name="GamCommands.txt" KeyPath="yes" />
-      </Component>
-''',
-    'GamUpdate.txt': '''      <Component Id="GamUpdate_txt" Guid="1b7cdd48-0fff-4943-a219-102fcd14c755">
-        <File Name="GamUpdate.txt" KeyPath="yes" />
-      </Component>
-''',
-    'cacerts.pem': '''      <Component Id="cacerts_pem" Guid="61fe2b2d-1646-4bed-b844-193965e97727">
-        <File Name="cacerts.pem" KeyPath="yes" />
-      </Component>
-''',
-}
-
-component_xml = ''
-all_files = []
-for root, dirs, files in os.walk(source_dir):
-    for filename in files:
-        relpath = os.path.relpath(root, source_dir)
-        if relpath == '.':
-            all_files.append(filename)
-        else:
-            all_files.append(os.path.join(relpath, filename))
-all_files.sort()
-for filename in all_files:
-    component_xml += existing_components.get(filename,
-                                             f'      <Component>\n        <File Name="{filename}" KeyPath="yes"/>\n      </Component>\n')
-
-with open(template_file, 'r') as f:
-    template = f.read()
-
-full_xml = template.replace('REPLACE_ME_WITH_FILE_COMPONENTS', component_xml)
-
-with open(target_file, 'w') as f:
-    f.write(full_xml)
+rewrite_file = sys.argv[1]
 
+with open(rewrite_file, 'rb') as f:
+    input_xml = f.read()
+root = etree.fromstring(input_xml)
+for elem in root.getiterator():
+    if 'Guid' in elem.attrib:
+        source = elem.getchildren()[0].attrib['Source']
+        stable_uuid = str(uuid.uuid5(uuid.NAMESPACE_URL, source))
+        elem.attrib['Guid'] = stable_uuid
+with open(rewrite_file, 'w') as f:
+  f.write(etree.tostring(root).decode())