diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,7 @@
+## 3.0.5.0
+
+* Avoid using the IsString Builder instance
+
 ## 3.0.4.0
 
 * A new module Network.Wai.HTTP2 is exported.
diff --git a/Network/Wai/HTTP2.hs b/Network/Wai/HTTP2.hs
--- a/Network/Wai/HTTP2.hs
+++ b/Network/Wai/HTTP2.hs
@@ -54,6 +54,7 @@
     ) where
 
 import           Blaze.ByteString.Builder (Builder)
+import           Blaze.ByteString.Builder.ByteString (fromByteString)
 import           Control.Exception (Exception, throwIO)
 import           Control.Monad.Trans.Cont (ContT(..))
 import           Data.ByteString (ByteString)
@@ -186,7 +187,7 @@
 -- | Respond with a minimal 404 page with the given headers.
 respondNotFound :: H.ResponseHeaders -> Responder
 respondNotFound h = Responder $ \k -> k H.notFound404 h' $
-    streamBuilder "File not found."
+    streamBuilder $ fromByteString "File not found."
   where
     contentType = (H.hContentType, "text/plain; charset=utf-8")
     h' = contentType:filter ((/=H.hContentType) . fst) h
diff --git a/wai.cabal b/wai.cabal
--- a/wai.cabal
+++ b/wai.cabal
@@ -1,5 +1,5 @@
 Name:                wai
-Version:             3.0.4.0
+Version:             3.0.5.0
 Synopsis:            Web Application Interface.
 Description:         Provides a common protocol for communication between web applications and web servers.
 description:         API docs and the README are available at <http://www.stackage.org/package/wai>.
@@ -20,7 +20,7 @@
 
 Library
   Build-Depends:     base                      >= 4        && < 5
-                   , bytestring                >= 0.9.1.4
+                   , bytestring                >= 0.10
                    , bytestring-builder        >= 0.10.4.0 && < 0.10.7
                    , blaze-builder             >= 0.2.1.4  && < 0.5
                    , network                   >= 2.2.1.5