diff --git a/bumblebee/theme.py b/bumblebee/theme.py
index 7fa8f65..16eb49a 100644
--- a/bumblebee/theme.py
+++ b/bumblebee/theme.py
@@ -233,7 +233,8 @@ class Theme(object):
             widget.set(key, (idx + 1) % len(value))
             value = value[idx]
 
-        if widget.get_module() is not None:
+        mod = widget.get_module()
+        if mod and not mod.parameter("is-unittest"):
             value = widget.get_module().parameter("theme.{}".format(name), value)
 
         if isinstance(value, list) or isinstance(value, dict):