diff --git a/yackage.cabal b/yackage.cabal
--- a/yackage.cabal
+++ b/yackage.cabal
@@ -1,5 +1,5 @@
 Name:                yackage
-Version:             0.5.0
+Version:             0.5.0.1
 Synopsis:            Personal Hackage replacement for testing new packages.
 Description:
     This package installs a yackage executable that runs a simplistic hackage-like server. It allows you to upload packages produced via cabal sdist and install them via cabal. The trick is to add the yackage repository to your cabal config file, with a line such as:
@@ -38,7 +38,7 @@
                      , hamlet
                      , yesod-form >= 1.0 && < 1.1
                      , http-types >= 0.6 && < 0.7
-                     , blaze-html
+                     , blaze-html >= 0.5 && < 0.6
                      , vector
                      , unordered-containers
 
diff --git a/yackage.hs b/yackage.hs
--- a/yackage.hs
+++ b/yackage.hs
@@ -3,6 +3,7 @@
 {-# LANGUAGE TemplateHaskell #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE FlexibleInstances #-}
 import Yesod.Core
 import Yesod.Dispatch
 import Yesod.Handler
@@ -42,7 +43,7 @@
 import Network.Wai.Handler.Warp (runSettings, defaultSettings, settingsPort, settingsHost)
 import Network.HTTP.Types (status403)
 import qualified Data.Text as T
-import Text.Blaze (toHtml)
+import Text.Blaze.Html (toHtml)
 import qualified Data.Vector as Vector
 
 data Args = Args