diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,7 @@
+## 1.6.0
+
+* Upgrade to yesod-core 1.6.0
+
 ## 1.4.1
 
 * Fix warnings
diff --git a/Yesod/EventSource.hs b/Yesod/EventSource.hs
--- a/Yesod/EventSource.hs
+++ b/Yesod/EventSource.hs
@@ -13,7 +13,7 @@
 import Data.Functor ((<$>))
 import Data.Monoid (Monoid (..))
 import Yesod.Core
-import qualified Data.Conduit as C
+import Data.Conduit
 import qualified Network.Wai as W
 import qualified Network.Wai.EventSource as ES
 import qualified Network.Wai.EventSource.EventStream as ES
@@ -32,32 +32,35 @@
 
 
 -- | (Internal) Source with a event stream content-type.
-respondEventStream :: C.Source (HandlerT site IO) (C.Flush Builder)
-                   -> HandlerT site IO TypedContent
+respondEventStream :: ConduitT () (Flush Builder) (HandlerFor site) ()
+                   -> HandlerFor site TypedContent
 respondEventStream = respondSource "text/event-stream"
 
 
--- | Returns a Server-Sent Event stream from a 'C.Source' of
+-- | Returns a Server-Sent Event stream from a 'Source' of
 -- 'ES.ServerEvent'@s@.  The HTTP socket is flushed after every
--- event.  The connection is closed either when the 'C.Source'
+-- event.  The connection is closed either when the 'Source'
 -- finishes outputting data or a 'ES.CloseEvent' is outputted,
 -- whichever comes first.
-repEventSource :: (EventSourcePolyfill -> C.Source (HandlerT site IO) ES.ServerEvent)
-               -> HandlerT site IO TypedContent
+repEventSource :: (EventSourcePolyfill -> ConduitT () ES.ServerEvent (HandlerFor site) ())
+               -> HandlerFor site TypedContent
 repEventSource src =
   prepareForEventSource >>=
   respondEventStream . sourceToSource . src
 
 -- | Convert a ServerEvent source into a Builder source of serialized
 -- events.
-sourceToSource :: Monad m => C.Source m ES.ServerEvent -> C.Source m (C.Flush Builder)
+sourceToSource
+  :: Monad m
+  => ConduitT () ES.ServerEvent m ()
+  -> ConduitT () (Flush Builder) m ()
 sourceToSource src =
-    src C.$= C.awaitForever eventToFlushBuilder
+    src .| awaitForever eventToFlushBuilder
   where
     eventToFlushBuilder event =
         case ES.eventToBuilder event of
             Nothing -> return ()
-            Just x -> C.yield (C.Chunk x) >> C.yield C.Flush
+            Just x -> yield (Chunk x) >> yield Flush
 
 
 -- | Return a Server-Sent Event stream given a 'HandlerT' action
@@ -68,8 +71,8 @@
 -- The connection is closed as soon as an 'ES.CloseEvent' is
 -- outputted, after which no other events are sent to the client.
 pollingEventSource :: s
-                   -> (EventSourcePolyfill -> s -> HandlerT site IO ([ES.ServerEvent], s))
-                   -> HandlerT site IO TypedContent
+                   -> (EventSourcePolyfill -> s -> HandlerFor site ([ES.ServerEvent], s))
+                   -> HandlerFor site TypedContent
 pollingEventSource initial act = do
   polyfill <- prepareForEventSource
   let -- Get new events to be sent.
@@ -79,8 +82,8 @@
           [] -> getEvents s'
           _  -> do
             let (builder, continue) = joinEvents evs mempty
-            C.yield (C.Chunk builder)
-            C.yield C.Flush
+            yield (Chunk builder)
+            yield Flush
             when continue (getEvents s')
 
       -- Join all events in a single Builder.  Returns @False@
@@ -103,7 +106,7 @@
 -- outputted, after which no other events are sent to the client.
 ioToRepEventSource :: s
                    -> (EventSourcePolyfill -> s -> IO ([ES.ServerEvent], s))
-                   -> HandlerT site IO TypedContent
+                   -> HandlerFor site TypedContent
 ioToRepEventSource initial act = pollingEventSource initial act'
   where act' p s = liftIO (act p s)
 
diff --git a/yesod-eventsource.cabal b/yesod-eventsource.cabal
--- a/yesod-eventsource.cabal
+++ b/yesod-eventsource.cabal
@@ -1,5 +1,5 @@
 name:            yesod-eventsource
-version:         1.4.1
+version:         1.6.0
 license:         MIT
 license-file:    LICENSE
 author:          Felipe Lessa <felipe.lessa@gmail.com>
@@ -15,8 +15,8 @@
 
 library
     build-depends:   base                  >= 4        && < 5
-                   , yesod-core            == 1.4.*
-                   , conduit               >= 0.5      && < 1.3
+                   , yesod-core            == 1.6.*
+                   , conduit               >= 1.3
                    , wai                   >= 1.3
                    , wai-eventsource       >= 1.3
                    , wai-extra