diff --git a/README.md b/README.md
index f2ada28..820fb8c 100644
--- a/README.md
+++ b/README.md
@@ -7,7 +7,7 @@ have extended and released under the same [`LICENSE`](./LICENSE)
 Installation
 ------------
 
-**The current version of this library requires gRPC version 1.2.0. Newer versions may work but have not been tested.**
+**The current version of this library requires gRPC version 1.34.1. Newer versions may work but have not been tested.**
 
 Usage
 -----
diff --git a/core/default.nix b/core/default.nix
deleted file mode 100644
index 5bfb04b..0000000
--- a/core/default.nix
+++ /dev/null
@@ -1,25 +0,0 @@
-{ mkDerivation, async, base, bytestring, c2hs, clock, containers
-, grpc, managed, pipes, proto3-suite, proto3-wire, QuickCheck, safe
-, sorted-list, stdenv, stm, tasty, tasty-hunit, tasty-quickcheck
-, text, time, transformers, turtle, unix, vector
-}:
-mkDerivation {
-  pname = "grpc-haskell-core";
-  version = "0.0.0.0";
-  src = ./.;
-  libraryHaskellDepends = [
-    async base bytestring clock containers managed pipes proto3-suite
-    proto3-wire safe sorted-list stm tasty tasty-hunit tasty-quickcheck
-    transformers vector
-  ];
-  librarySystemDepends = [ grpc ];
-  libraryToolDepends = [ c2hs ];
-  testHaskellDepends = [
-    async base bytestring clock containers managed pipes proto3-suite
-    QuickCheck safe tasty tasty-hunit tasty-quickcheck text time
-    transformers turtle unix
-  ];
-  homepage = "https://github.com/awakenetworks/gRPC-haskell";
-  description = "Haskell implementation of gRPC layered on shared C library";
-  license = stdenv.lib.licenses.asl20;
-}
diff --git a/core/grpc-haskell-core.cabal b/core/grpc-haskell-core.cabal
index d80bbb7..f88a634 100644
--- a/core/grpc-haskell-core.cabal
+++ b/core/grpc-haskell-core.cabal
@@ -68,7 +68,7 @@ library
     , grpc/slice.h
   build-tools:          c2hs
   default-language:     Haskell2010
-  ghc-options:          -Wall -fwarn-incomplete-patterns -fno-warn-unused-do-bind
+  ghc-options:          -Wall -Werror -fwarn-incomplete-patterns -fno-warn-unused-do-bind
   include-dirs:         include
   hs-source-dirs:       src
   default-extensions:   CPP
@@ -103,7 +103,7 @@ test-suite tests
     LowLevelTests.Op,
     UnsafeTests
   default-language:     Haskell2010
-  ghc-options:          -Wall -fwarn-incomplete-patterns -fno-warn-unused-do-bind -g -threaded -rtsopts
+  ghc-options:          -Wall -Werror -fwarn-incomplete-patterns -fno-warn-unused-do-bind -g -threaded -rtsopts
   hs-source-dirs:       tests
   main-is:              Properties.hs
   type:                 exitcode-stdio-1.0
diff --git a/core/src/Network/GRPC/LowLevel/Call.hs b/core/src/Network/GRPC/LowLevel/Call.hs
index 6c108d9..9962ce0 100644
--- a/core/src/Network/GRPC/LowLevel/Call.hs
+++ b/core/src/Network/GRPC/LowLevel/Call.hs
@@ -5,7 +5,7 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE KindSignatures             #-}
 {-# LANGUAGE OverloadedStrings          #-}
-{-# LANGUAGE RecordWildCards            #-}
+{-# LANGUAGE NamedFieldPuns             #-}
 {-# LANGUAGE ScopedTypeVariables        #-}
 {-# LANGUAGE StandaloneDeriving         #-}
 {-# LANGUAGE TypeFamilies               #-}
@@ -212,8 +212,8 @@ destroyClientCall cc = do
   C.grpcCallUnref (unsafeCC cc)
 
 destroyServerCall :: ServerCall a -> IO ()
-destroyServerCall sc@ServerCall{ unsafeSC = c, .. } = do
+destroyServerCall sc@ServerCall{ unsafeSC } = do
   grpcDebug "destroyServerCall(R): entered."
   debugServerCall sc
-  grpcDebug $ "Destroying server-side call object: " ++ show c
-  C.grpcCallUnref c
+  grpcDebug $ "Destroying server-side call object: " ++ show unsafeSC
+  C.grpcCallUnref unsafeSC
diff --git a/core/src/Network/GRPC/LowLevel/CompletionQueue.hs b/core/src/Network/GRPC/LowLevel/CompletionQueue.hs
index ae7a9d7..a1edbc8 100644
--- a/core/src/Network/GRPC/LowLevel/CompletionQueue.hs
+++ b/core/src/Network/GRPC/LowLevel/CompletionQueue.hs
@@ -71,7 +71,7 @@ createCompletionQueue _ = do
 -- Throws 'CallError' if 'grpcCallStartBatch' returns a non-OK code.
 startBatch :: CompletionQueue -> C.Call -> C.OpArray -> Int -> C.Tag
               -> IO (Either GRPCIOError ())
-startBatch cq@CompletionQueue{..} call opArray opArraySize tag =
+startBatch cq call opArray opArraySize tag =
     withPermission Push cq $ fmap throwIfCallError $ do
       grpcDebug $ "startBatch: calling grpc_call_start_batch with pointers: "
                   ++ show call ++ " " ++ show opArray
diff --git a/core/src/Network/GRPC/LowLevel/CompletionQueue/Internal.hs b/core/src/Network/GRPC/LowLevel/CompletionQueue/Internal.hs
index db63632..8fd2d54 100644
--- a/core/src/Network/GRPC/LowLevel/CompletionQueue/Internal.hs
+++ b/core/src/Network/GRPC/LowLevel/CompletionQueue/Internal.hs
@@ -104,7 +104,7 @@ withPermission op cq act = bracket acquire release $ \gotResource ->
 -- 'serverRequestCall', this will block forever unless a timeout is given.
 pluck :: CompletionQueue -> C.Tag -> Maybe TimeoutSeconds
          -> IO (Either GRPCIOError ())
-pluck cq@CompletionQueue{..} tag mwait = do
+pluck cq tag mwait = do
   grpcDebug $ "pluck: called with tag=" ++ show tag ++ ",mwait=" ++ show mwait
   withPermission Pluck cq $ pluck' cq tag mwait
 
diff --git a/core/src/Network/GRPC/Unsafe.chs b/core/src/Network/GRPC/Unsafe.chs
index 6eb08b8..8967537 100644
--- a/core/src/Network/GRPC/Unsafe.chs
+++ b/core/src/Network/GRPC/Unsafe.chs
@@ -7,7 +7,6 @@ import Control.Exception (bracket)
 import Control.Monad
 
 import Data.ByteString (ByteString, useAsCString)
-import Data.Semigroup (Semigroup)
 
 import Foreign.C.String (CString, peekCString)
 import Foreign.Marshal.Alloc (free)
diff --git a/core/src/Network/GRPC/Unsafe/Metadata.chs b/core/src/Network/GRPC/Unsafe/Metadata.chs
index 270ca0a..57db2ae 100644
--- a/core/src/Network/GRPC/Unsafe/Metadata.chs
+++ b/core/src/Network/GRPC/Unsafe/Metadata.chs
@@ -12,7 +12,6 @@ import Data.Function (on)
 import Data.ByteString (ByteString, useAsCString,
                         useAsCStringLen)
 import Data.List (sortBy, groupBy)
-import Data.Semigroup (Semigroup((<>)))
 import qualified Data.SortedList as SL
 import qualified Data.Map.Strict as M
 import Data.Ord (comparing)
diff --git a/core/tests/LowLevelTests.hs b/core/tests/LowLevelTests.hs
index 75867ab..7663cb3 100644
--- a/core/tests/LowLevelTests.hs
+++ b/core/tests/LowLevelTests.hs
@@ -22,7 +22,6 @@ import           Data.List                                 (find)
 import qualified Data.Map.Strict                           as M
 import qualified Data.Set                                  as S
 import           GHC.Exts                                  (fromList, toList)
-import           Network.GRPC.Unsafe.ChannelArgs           (Arg(..))
 import           Network.GRPC.LowLevel
 import qualified Network.GRPC.LowLevel.Call.Unregistered   as U
 import qualified Network.GRPC.LowLevel.Client.Unregistered as U
@@ -183,7 +182,7 @@ testSSL =
                                         Nothing)
                   }
     server = TestServer serverConf' $ \s -> do
-      r <- U.serverHandleNormalCall s mempty $ \U.ServerCall{..} body -> do
+      r <- U.serverHandleNormalCall s mempty $ \U.ServerCall{} body -> do
         body @?= "hi"
         return ("reply test", mempty, StatusOk, "")
       r @?= Right ()
@@ -282,7 +281,7 @@ testAuthMetadataTransfer =
                                         serverProcessor)
                   }
     server = TestServer serverConf' $ \s -> do
-      r <- U.serverHandleNormalCall s mempty $ \U.ServerCall{..} body -> do
+      r <- U.serverHandleNormalCall s mempty $ \U.ServerCall{} body -> do
         body @?= "hi"
         return ("reply test", mempty, StatusOk, "")
       r @?= Right ()
diff --git a/core/tests/LowLevelTests/Op.hs b/core/tests/LowLevelTests/Op.hs
index dae4ba7..ade46ec 100644
--- a/core/tests/LowLevelTests/Op.hs
+++ b/core/tests/LowLevelTests/Op.hs
@@ -27,7 +27,7 @@ testCancelFromServer =
   testCase "Client/Server - client receives server cancellation" $
     runSerialTest $ \grpc ->
       withClientServerUnaryCall grpc $
-        \(Client {..}, Server {..}, ClientCall {..}, sc@ServerCall {..}) -> do
+        \(Client {..}, Server {}, ClientCall {..}, sc@ServerCall {}) -> do
           serverCallCancel sc StatusPermissionDenied "TestStatus"
           clientRes <- runOps unsafeCC clientCQ clientRecvOps
           case clientRes of
diff --git a/core/tests/UnsafeTests.hs b/core/tests/UnsafeTests.hs
index e335324..b009e9c 100644
--- a/core/tests/UnsafeTests.hs
+++ b/core/tests/UnsafeTests.hs
@@ -20,7 +20,6 @@ import           Network.GRPC.Unsafe.Slice
 import           Network.GRPC.Unsafe.Time
 import           System.Clock
 import           Test.QuickCheck.Gen
-import qualified Test.QuickCheck.Property        as QC
 import           Test.Tasty
 import           Test.Tasty.HUnit                as HU (testCase, (@?=))
 import           Test.Tasty.QuickCheck           as QC
diff --git a/examples/echo/echo-hs/EchoClient.hs b/examples/echo/echo-hs/EchoClient.hs
index 1a72fd0..a51c238 100644
--- a/examples/echo/echo-hs/EchoClient.hs
+++ b/examples/echo/echo-hs/EchoClient.hs
@@ -12,7 +12,6 @@ import           Data.ByteString                  (ByteString)
 import           Data.Maybe                       (fromMaybe)
 import qualified Data.Text.Lazy                   as TL
 import           Echo
-import           GHC.Generics                     (Generic)
 import           Network.GRPC.HighLevel.Client
 import           Network.GRPC.LowLevel
 import           Options.Generic
diff --git a/examples/echo/echo-hs/EchoServer.hs b/examples/echo/echo-hs/EchoServer.hs
index b147117..653d727 100644
--- a/examples/echo/echo-hs/EchoServer.hs
+++ b/examples/echo/echo-hs/EchoServer.hs
@@ -9,7 +9,6 @@
 
 import           Data.ByteString                  (ByteString)
 import           Data.Maybe                       (fromMaybe)
-import           GHC.Generics                     (Generic)
 import           Network.GRPC.HighLevel.Generated (GRPCMethodType (..),
                                                    Host (..), Port (..),
                                                    ServerRequest (..),
diff --git a/grpc-haskell.cabal b/grpc-haskell.cabal
index d149a41..5bdd245 100644
--- a/grpc-haskell.cabal
+++ b/grpc-haskell.cabal
@@ -42,7 +42,7 @@ library
     Network.GRPC.HighLevel.Server.Unregistered
     Network.GRPC.HighLevel.Client
   default-language:     Haskell2010
-  ghc-options:          -Wall -fwarn-incomplete-patterns -fno-warn-unused-do-bind
+  ghc-options:          -Wall -Werror -fwarn-incomplete-patterns -fno-warn-unused-do-bind
   hs-source-dirs:       src
   default-extensions:   CPP
   CC-Options: -std=c99
@@ -66,7 +66,7 @@ executable hellos-server
   else
     buildable: False
   default-language: Haskell2010
-  ghc-options:      -Wall -g -threaded -rtsopts -with-rtsopts=-N -O2
+  ghc-options:      -Wall -Werror -g -threaded -rtsopts -with-rtsopts=-N -O2
   hs-source-dirs:   examples/hellos/hellos-server
   main-is:          Main.hs
 
@@ -86,7 +86,7 @@ executable hellos-client
   else
     buildable: False
   default-language: Haskell2010
-  ghc-options:      -Wall -g -threaded -rtsopts -with-rtsopts=-N -O2
+  ghc-options:      -Wall -Werror -g -threaded -rtsopts -with-rtsopts=-N -O2
   hs-source-dirs:   examples/hellos/hellos-client
   main-is:          Main.hs
 
@@ -110,7 +110,7 @@ executable echo-server
   else
     buildable: False
   default-language: Haskell2010
-  ghc-options:      -Wall -g -threaded -rtsopts -with-rtsopts=-N -O2
+  ghc-options:      -Wall -Werror -g -threaded -rtsopts -with-rtsopts=-N -O2
   hs-source-dirs:   examples/echo/echo-hs
   main-is:          EchoServer.hs
 
@@ -135,7 +135,7 @@ executable arithmetic-server
   else
     buildable: False
   default-language: Haskell2010
-  ghc-options:      -Wall -g -threaded -rtsopts -with-rtsopts=-N -O2
+  ghc-options:      -Wall -Werror -g -threaded -rtsopts -with-rtsopts=-N -O2
   hs-source-dirs:   examples/tutorial/
   main-is:          ArithmeticServer.hs
 
@@ -159,7 +159,7 @@ executable arithmetic-client
   else
     buildable: False
   default-language: Haskell2010
-  ghc-options:      -Wall -g -threaded -rtsopts -with-rtsopts=-N -O2
+  ghc-options:      -Wall -Werror -g -threaded -rtsopts -with-rtsopts=-N -O2
   hs-source-dirs:   examples/tutorial/
   main-is:          ArithmeticClient.hs
 
@@ -184,14 +184,13 @@ executable echo-client
   else
     buildable: False
   default-language: Haskell2010
-  ghc-options:      -Wall -g -threaded -rtsopts -with-rtsopts=-N -O2
+  ghc-options:      -Wall -Werror -g -threaded -rtsopts -with-rtsopts=-N -O2
   hs-source-dirs:   examples/echo/echo-hs
   main-is:          EchoClient.hs
 
 test-suite tests
   build-depends:
       base >=4.8 && <5.0
-    , grpc-haskell
     , bytestring ==0.10.*
     , unix
     , time
@@ -212,7 +211,7 @@ test-suite tests
   other-modules:
     GeneratedTests
   default-language:     Haskell2010
-  ghc-options:          -Wall -fwarn-incomplete-patterns -fno-warn-unused-do-bind -g -threaded -rtsopts
+  ghc-options:          -Wall -Werror -fwarn-incomplete-patterns -fno-warn-unused-do-bind -g -threaded -rtsopts
   hs-source-dirs:       tests
   main-is:              Properties.hs
   type:                 exitcode-stdio-1.0
@@ -233,7 +232,7 @@ benchmark bench
     , random >=1.0.0
   hs-source-dirs: bench
   main-is: Bench.hs
-  ghc-options:      -Wall -O2 -threaded -rtsopts -with-rtsopts=-N
+  ghc-options:      -Wall -Werror -O2 -threaded -rtsopts -with-rtsopts=-N
   if flag(debug)
     CPP-Options: -DDEBUG
     CC-Options:  -DGRPC_HASKELL_DEBUG
diff --git a/release.nix b/release.nix
index 8d8542a..a5848e1 100644
--- a/release.nix
+++ b/release.nix
@@ -94,9 +94,11 @@ let
 
         grpc-haskell-core =
           pkgsNew.haskell.lib.buildFromSdist (pkgsNew.usesGRPC
-            (pkgsNew.haskell.lib.overrideCabal
-              (haskellPackagesNew.callPackage ./core { })
-              (_: { buildDepends = [ haskellPackagesNew.c2hs ]; })));
+            (haskellPackagesNew.callCabal2nix "grpc-haskell-core" ./core {
+                 gpr = pkgsNew.grpc;
+               }
+            )
+          );
 
         grpc-haskell-no-tests =
           pkgsNew.haskell.lib.buildFromSdist (pkgsNew.usesGRPC
@@ -120,7 +122,6 @@ let
                     ]);
 
                   python = pkgsNew.python.withPackages (pkgs: [
-                    # pkgs.protobuf3_0
                     pkgs.grpcio-tools
                   ]);
 
@@ -173,11 +174,6 @@ let
       };
     };
 
-    protobuf3_2NoCheck =
-      pkgsNew.stdenv.lib.overrideDerivation
-        pkgsNew.pythonPackages.protobuf
-        (oldAttrs : {doCheck = false; doInstallCheck = false;});
-
     test-grpc-haskell =
       pkgsNew.mkShell {
         nativeBuildInputs = [
@@ -190,21 +186,15 @@ let
       };
 
     usesGRPC = haskellPackage:
+      # TODO: Try using pkgsNew.fixDarwinDylibNames (see PR#129).
       pkgsNew.haskell.lib.overrideCabal haskellPackage (oldAttributes: {
           preBuild = (oldAttributes.preBuild or "") +
             pkgsNew.lib.optionalString pkgsNew.stdenv.isDarwin ''
               export DYLD_LIBRARY_PATH=${pkgsNew.grpc}/lib''${DYLD_LIBRARY_PATH:+:}$DYLD_LIBRARY_PATH
-            '' +
-            pkgsNew.lib.optionalString pkgsNew.stdenv.isLinux ''
-              export LD_LIBRARY_PATH=${pkgsNew.grpc}/lib''${LD_LIBRARY_PATH:+:}$LD_LIBRARY_PATH
             '';
-
           shellHook = (oldAttributes.shellHook or "") +
             pkgsNew.lib.optionalString pkgsNew.stdenv.isDarwin ''
               export DYLD_LIBRARY_PATH=${pkgsNew.grpc}/lib''${DYLD_LIBRARY_PATH:+:}$DYLD_LIBRARY_PATH
-            '' +
-            pkgsNew.lib.optionalString pkgsNew.stdenv.isLinux ''
-              export LD_LIBRARY_PATH=${pkgsNew.grpc}/lib''${LD_LIBRARY_PATH:+:}$LD_LIBRARY_PATH
             '';
         }
       );