diff --git a/prometheus.cabal b/prometheus.cabal
--- a/prometheus.cabal
+++ b/prometheus.cabal
@@ -1,5 +1,5 @@
 name:                prometheus
-version:             0.3.2.1
+version:             0.4.0
 synopsis:            Prometheus Haskell Client
 homepage:            http://github.com/LukeHoersten/prometheus#readme
 bug-reports:         http://github.com/LukeHoersten/prometheus/issues
@@ -74,12 +74,12 @@
                  , System.Metrics.Prometheus.RegistryT
 
   build-depends: atomic-primops >= 0.8  && < 0.9
-               , base           >= 4.7  && < 5.0
+               , base           >= 4.7  && < 4.10
                , bytestring     >= 0.10 && < 0.11
                , containers     >= 0.5  && < 0.6
                , http-types     >= 0.9  && < 0.10
                , text           >= 1.2  && < 1.3
-               , transformers   >= 0.4  && < 0.5
+               , transformers   >= 0.4  && < 0.6
                , wai            >= 3.2  && < 3.3
                , warp           >= 3.2  && < 3.3
 
diff --git a/src/System/Metrics/Prometheus/Concurrent/Http.hs b/src/System/Metrics/Prometheus/Concurrent/Http.hs
--- a/src/System/Metrics/Prometheus/Concurrent/Http.hs
+++ b/src/System/Metrics/Prometheus/Concurrent/Http.hs
@@ -1,6 +1,12 @@
 {-# LANGUAGE OverloadedStrings #-}
 
-module System.Metrics.Prometheus.Concurrent.Http where
+module System.Metrics.Prometheus.Concurrent.Http
+       ( Path
+       , serveHttpTextMetrics
+       , serveHttpTextMetricsT
+       , prometheusApp
+       )
+       where
 
 import           Control.Monad.IO.Class                         (MonadIO,
                                                                  liftIO)
@@ -28,15 +34,15 @@
 
 
 serveHttpTextMetrics :: MonadIO m => Port -> Path -> IO RegistrySample -> m ()
-serveHttpTextMetrics port path = liftIO . run port . app path
+serveHttpTextMetrics port path = liftIO . run port . prometheusApp path
 
 
 serveHttpTextMetricsT :: MonadIO m => Port -> Path -> RegistryT m ()
 serveHttpTextMetricsT port path = liftIO . serveHttpTextMetrics port path =<< sample
 
 
-app :: Path -> IO RegistrySample -> Application
-app path runSample request respond
+prometheusApp :: Path -> IO RegistrySample -> Application
+prometheusApp path runSample request respond
     | isPrometheusRequest path request = respond =<< prometheusResponse <$> runSample
     | otherwise = respond response404
   where