diff --git a/src/UrlPath.hs b/src/UrlPath.hs
--- a/src/UrlPath.hs
+++ b/src/UrlPath.hs
@@ -48,7 +48,7 @@
   runUrlReader = runGroundedUrl
 
 -- | @Url@ takes an input type @a@, and returns a modality @f@ around @T.Text@.
-class Monad m => Url a m where
+class MonadReader T.Text m => Url a m where
   renderUrl :: a -- ^ Url-like type (@UrlString@ or @T.Text@).
             -> m T.Text -- ^ Rendered Url in some context @f@
 
diff --git a/urlpath.cabal b/urlpath.cabal
--- a/urlpath.cabal
+++ b/urlpath.cabal
@@ -1,5 +1,5 @@
 Name:                   urlpath
-Version:                0.0.5
+Version:                0.0.6
 Author:                 Athan Clark <athan.clark@gmail.com>
 Maintainer:             Athan Clark <athan.clark@gmail.com>
 License:                MIT