diff --git a/modules/localization.py b/modules/localization.py
index f6a6f2fbd..ee9c65e7d 100644
--- a/modules/localization.py
+++ b/modules/localization.py
@@ -23,7 +23,7 @@ def list_localizations(dirname):
         localizations[fn] = file.path
 
 
-def localization_js(current_localization_name):
+def localization_js(current_localization_name: str) -> str:
     fn = localizations.get(current_localization_name, None)
     data = {}
     if fn is not None:
@@ -34,4 +34,4 @@ def localization_js(current_localization_name):
             print(f"Error loading localization from {fn}:", file=sys.stderr)
             print(traceback.format_exc(), file=sys.stderr)
 
-    return f"var localization = {json.dumps(data)}\n"
+    return f"window.localization = {json.dumps(data)}"
diff --git a/modules/ui.py b/modules/ui.py
index ff82fff6c..ff25c4ce9 100644
--- a/modules/ui.py
+++ b/modules/ui.py
@@ -1771,12 +1771,11 @@ def webpath(fn):
 
 
 def javascript_html():
-    script_js = os.path.join(script_path, "script.js")
-    head = f'<script type="text/javascript" src="{webpath(script_js)}"></script>\n'
+    # Ensure localization is in `window` before scripts
+    head = f'<script type="text/javascript">{localization.localization_js(shared.opts.localization)}</script>\n'
 
-    inline = f"{localization.localization_js(shared.opts.localization)};"
-    if cmd_opts.theme is not None:
-        inline += f"set_theme('{cmd_opts.theme}');"
+    script_js = os.path.join(script_path, "script.js")
+    head += f'<script type="text/javascript" src="{webpath(script_js)}"></script>\n'
 
     for script in modules.scripts.list_scripts("javascript", ".js"):
         head += f'<script type="text/javascript" src="{webpath(script.path)}"></script>\n'
@@ -1784,7 +1783,8 @@ def javascript_html():
     for script in modules.scripts.list_scripts("javascript", ".mjs"):
         head += f'<script type="module" src="{webpath(script.path)}"></script>\n'
 
-    head += f'<script type="text/javascript">{inline}</script>\n'
+    if cmd_opts.theme:
+        head += f'<script type="text/javascript">set_theme(\"{cmd_opts.theme}\");</script>\n'
 
     return head