diff --git a/src/Network/Wai/Middleware/Prometheus.hs b/src/Network/Wai/Middleware/Prometheus.hs
--- a/src/Network/Wai/Middleware/Prometheus.hs
+++ b/src/Network/Wai/Middleware/Prometheus.hs
@@ -8,11 +8,14 @@
 ,   Default.def
 ,   instrumentApp
 ,   instrumentIO
+,   metricsApp
 ) where
 
-import Data.Time.Clock (diffUTCTime, getCurrentTime)
+import Data.Time.Clock (UTCTime, diffUTCTime, getCurrentTime)
 import qualified Data.ByteString.Builder as BS
+import qualified Data.ByteString.Char8 as BS
 import qualified Data.Default as Default
+import Data.Maybe (fromMaybe)
 import qualified Data.Text as T
 import qualified Network.HTTP.Types as HTTP
 import qualified Network.Wai as Wai
@@ -43,8 +46,10 @@
     }
 
 {-# NOINLINE requestLatency #-}
-requestLatency :: Prom.Metric (Prom.Vector Prom.Label1 Prom.Summary)
-requestLatency = Prom.unsafeRegisterIO $ Prom.vector "handler"
+-- XXX: https://prometheus.io/docs/practices/naming/ says this should be
+-- _seconds, not _microseconds.
+requestLatency :: Prom.Metric (Prom.Vector Prom.Label3 Prom.Summary)
+requestLatency = Prom.unsafeRegisterIO $ Prom.vector ("handler", "method", "status_code")
                                        $ Prom.summary info Prom.defaultQuantiles
     where info = Prom.Info "http_request_duration_microseconds"
                            "The HTTP request latencies in microseconds."
@@ -57,8 +62,14 @@
 instrumentApp :: String           -- ^ The label used to identify this app
               -> Wai.Application  -- ^ The app to instrument
               -> Wai.Application  -- ^ The instrumented app
-instrumentApp handler app req respond =
-    observeMicroSeconds handler (app req respond)
+instrumentApp handler app req respond = do
+    start <- getCurrentTime
+    app req $ \res -> do
+        end <- getCurrentTime
+        let method = Just $ BS.unpack (Wai.requestMethod req)
+        let status = Just $ show (HTTP.statusCode (Wai.responseStatus res))
+        observeMicroSeconds handler method status start end
+        respond res
 
 -- | Instrument an IO action with timing metrics. This function can be used if
 -- you would like to get more fine grained metrics, for instance this can be
@@ -70,31 +81,36 @@
 instrumentIO :: String  -- ^ The label used to identify this IO operation
              -> IO a    -- ^ The IO action to instrument
              -> IO a    -- ^ The instrumented app
-instrumentIO = observeMicroSeconds
-
-observeMicroSeconds :: String -> IO a -> IO a
-observeMicroSeconds handler io = do
+instrumentIO label io = do
     start  <- getCurrentTime
     result <- io
     end    <- getCurrentTime
-    let latency = fromRational $ toRational (end `diffUTCTime` start) * 1000000
-    Prom.withLabel handler (Prom.observe latency) requestLatency
+    observeMicroSeconds label Nothing Nothing start end
     return result
 
+observeMicroSeconds :: String -> Maybe String -> Maybe String -> UTCTime -> UTCTime -> IO ()
+observeMicroSeconds handler method status start end = do
+    let latency = fromRational $ toRational (end `diffUTCTime` start) * 1000000
+    Prom.withLabel (handler, fromMaybe "" method, fromMaybe "" status)
+                   (Prom.observe latency)
+                   requestLatency
+
 -- | Expose Prometheus metrics and instrument an application with some basic
 -- metrics (e.g. request latency).
 prometheus :: PrometheusSettings -> Wai.Middleware
 prometheus PrometheusSettings{..} app req respond =
     if     Wai.requestMethod req == HTTP.methodGet
         && Wai.pathInfo req == prometheusEndPoint
-    then measure measureMetrics "prometheus" $ respondWithMetrics respond
-    else measure measureApp "app" $ app req respond
-    where
-        measureMetrics = prometheusInstrumentPrometheus
-        measureApp = prometheusInstrumentApp
-        measure shouldInstrument handler io
-            | shouldInstrument = observeMicroSeconds handler io
-            | otherwise        = io
+        -- XXX: Should probably be "metrics" rather than "prometheus", since
+        -- "prometheus" can be confused with actual prometheus.
+    then instrumentApp "prometheus" (const respondWithMetrics) req respond
+    else instrumentApp "app" app req respond
+
+
+-- | WAI Application that serves the Prometheus metrics page regardless of
+-- what the request is.
+metricsApp :: Wai.Application
+metricsApp = const respondWithMetrics
 
 respondWithMetrics :: (Wai.Response -> IO Wai.ResponseReceived)
                    -> IO Wai.ResponseReceived
diff --git a/wai-middleware-prometheus.cabal b/wai-middleware-prometheus.cabal
--- a/wai-middleware-prometheus.cabal
+++ b/wai-middleware-prometheus.cabal
@@ -1,5 +1,5 @@
 name:                wai-middleware-prometheus
-version:             0.1.0.1
+version:             0.1.1
 synopsis:
     WAI middlware for exposing http://prometheus.io metrics.
 description: