diff --git a/tailbone/subscribers.py b/tailbone/subscribers.py
index 1143b510..d05b8bd5 100644
--- a/tailbone/subscribers.py
+++ b/tailbone/subscribers.py
@@ -40,7 +40,7 @@ from tailbone import helpers
 from tailbone.db import Session
 from tailbone.config import csrf_header_name, should_expose_websockets
 from tailbone.menus import make_simple_menus
-from tailbone.util import get_global_search_options
+from tailbone.util import get_available_themes, get_global_search_options
 
 
 def new_request(event):
@@ -152,12 +152,11 @@ def before_render(event):
                                                        default=False)
         renderer_globals['expose_theme_picker'] = expose_picker
         if expose_picker:
-            # tailbone's config extension provides a default theme selection,
-            # so the default we specify here *probably* should not matter
-            available = request.rattail_config.getlist('tailbone', 'themes',
-                                                       default=['falafel'])
-            if 'default' not in available:
-                available.insert(0, 'default')
+
+            # TODO: should remove 'falafel' option altogether
+            available = get_available_themes(request.rattail_config,
+                                             include=['falafel'])
+
             options = [tags.Option(theme, value=theme) for theme in available]
             renderer_globals['theme_picker_options'] = options
 
diff --git a/tailbone/util.py b/tailbone/util.py
index 4c9c680e..01efdce4 100644
--- a/tailbone/util.py
+++ b/tailbone/util.py
@@ -333,6 +333,26 @@ def get_theme_template_path(rattail_config, theme=None, session=None):
     return resource_path(theme_path)
 
 
+def get_available_themes(rattail_config, include=None):
+    available = rattail_config.getlist('tailbone', 'themes.keys')
+    if not available:
+        available = rattail_config.getlist('tailbone', 'themes',
+                                           ignore_ambiguous=True)
+        if available:
+            warnings.warn(f"URGENT: instead of 'tailbone.themes', "
+                          f"you should set 'tailbone.themes.keys'",
+                          DeprecationWarning, stacklevel=2)
+        else:
+            available = []
+    if 'default' not in available:
+        available.insert(0, 'default')
+    if include is not None:
+        for theme in include:
+            if theme not in available:
+                available.append(theme)
+    return available
+
+
 def get_effective_theme(rattail_config, theme=None, session=None):
     """
     Validates and returns the "effective" theme.  If you provide a theme, that
@@ -350,9 +370,7 @@ def get_effective_theme(rattail_config, theme=None, session=None):
             session.close()
 
     # confirm requested theme is available
-    available = rattail_config.getlist('tailbone', 'themes',
-                                       default=['bobcat'])
-    available.append('default')
+    available = get_available_themes(rattail_config)
     if theme not in available:
         raise ValueError("theme not available: {}".format(theme))