diff --git a/deluge/ui/web/server.py b/deluge/ui/web/server.py
index ae339dd44..b83cd4a18 100644
--- a/deluge/ui/web/server.py
+++ b/deluge/ui/web/server.py
@@ -564,15 +564,15 @@ class TopLevel(resource.Resource):
 
     def render(self, request):
         uri_true = ('true', 'yes', '1')
-        debug_arg = request.args.get('debug', [''])[-1] in uri_true
-        dev_arg = request.args.get('dev', [''])[-1] in uri_true
+        debug_arg = request.args.get('debug', [b''])[-1].decode().lower() in uri_true
+        dev_arg = request.args.get('dev', [b''])[-1].decode().lower() in uri_true
         dev_ver = 'dev' in common.get_version()
 
         script_type = 'normal'
         if debug_arg:
             script_type = 'debug'
-        # Override debug if dev arg or version.
-        if dev_arg or dev_ver:
+        elif dev_arg or dev_ver:
+            # Also use dev files if development version.
             script_type = 'dev'
 
         if not self.js.has_script_type_files(script_type):
@@ -581,9 +581,10 @@ class TopLevel(resource.Resource):
                     'Failed to enable WebUI "%s" mode, script files are missing!',
                     script_type,
                 )
-            # Fallback to checking other types in order and selecting first with files available.
+            # Fallback to checking other types in order and selecting first with
+            # files available. Ordered to start with dev files lookup.
             for alt_script_type in [
-                x for x in ['normal', 'debug', 'dev'] if x != script_type
+                x for x in ['dev', 'debug', 'normal'] if x != script_type
             ]:
                 if self.js.has_script_type_files(alt_script_type):
                     script_type = alt_script_type
diff --git a/setup.py b/setup.py
index d9c7ae3f5..db45b0f7a 100755
--- a/setup.py
+++ b/setup.py
@@ -162,6 +162,8 @@ class CleanWebUI(cmd.Command):
 
     def run(self):
         js_basedir = os.path.join(os.path.dirname(__file__), BuildWebUI.JS_DIR)
+
+        # Remove files generated by minify script.
         for js_src_dir in BuildWebUI.JS_SRC_DIRS:
             for file_type in ('.js', '-debug.js'):
                 js_file = os.path.join(js_basedir, js_src_dir + file_type)
@@ -171,6 +173,14 @@ class CleanWebUI(cmd.Command):
                 except OSError:
                     pass
 
+        # Remove generated gettext.js
+        js_file = os.path.join(js_basedir, 'gettext.js')
+        print('Deleting {}'.format(js_file))
+        try:
+            os.remove(js_file)
+        except OSError:
+            pass
+
 
 class BuildTranslations(cmd.Command):
     description = 'Compile .po files into .mo files & create .desktop file'
@@ -532,9 +542,6 @@ _package_data['deluge.ui.web'] = [
 ]
 _package_data['deluge.ui.gtkui'] = ['glade/*.ui']
 
-if 'dev' not in _version:
-    _exclude_package_data['deluge.ui.web'] = ['*-debug.js', '*-debug.css']
-
 docs_require = ['sphinx', 'recommonmark', 'sphinx-rtd-theme']
 tests_require = [
     'coverage',