diff --git a/multipool-postgresql-simple.cabal b/multipool-postgresql-simple.cabal
--- a/multipool-postgresql-simple.cabal
+++ b/multipool-postgresql-simple.cabal
@@ -4,10 +4,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: e42319132652ad23030c5f6a93f113a4b36f2ca1a07bd8bdd2e3dab102c9b922
+-- hash: 39b87d51ca23fd8005d4fb7bc4a7899f7b8c90c501434f88e101144678f35196
 
 name:           multipool-postgresql-simple
-version:        0.1.0.2
+version:        0.2.0.0
 description:    Please see the README on GitHub at <https://github.com/iand675/multipool-postgresql-simple#readme>
 homepage:       https://github.com/iand675/multipool#readme
 bug-reports:    https://github.com/iand675/multipool/issues
diff --git a/src/Data/MultiPool/PostgreSQLSimple.hs b/src/Data/MultiPool/PostgreSQLSimple.hs
--- a/src/Data/MultiPool/PostgreSQLSimple.hs
+++ b/src/Data/MultiPool/PostgreSQLSimple.hs
@@ -38,15 +38,15 @@
 initMultiPool' ::
      (MonadUnliftIO m)
   => (MultiPool Connection -> IO (Maybe (InstanceName Connection))) -- Strategy for selectin the replica instance when calling 'runReadAny'. 'roundRobin' is the current default.
-  -> ByteString -- ^ Master connection string
+  -> ByteString -- ^ Primary connection string
   -> Int -- ^ Max number of connections to master instance
   -> [(InstanceName Connection, ByteString, Int)] -- ^ Replica connection details
   -> m (MultiPool Connection)
 initMultiPool' multiPoolAnyReplicaSelector str n is = do
-  multiPoolMaster <- liftIO $ createPool (connectPostgreSQL str) close n 15 1
+  multiPoolPrimary <- liftIO $ createPool (connectPostgreSQL str) close n 15 1
   replicas <- liftIO $ mapM (\(inst, connStr, numConns) -> (,) <$> pure inst <*> createPool (connectPostgreSQL connStr) close numConns 15 1) is
   let multiPoolReplica = HM.fromList replicas
-      multiPoolAnyMasterSelector = const $ pure ()
+      multiPoolAnyPrimarySelector = const $ pure ()
   return $ MultiPool {..}
 
 withResource' :: MonadUnliftIO m => Pool a -> (a -> m b) -> m b
@@ -56,20 +56,28 @@
       io $ action a
 
 instance MonadUnliftIO m => MultiPoolBackend m Connection where
-  type MasterConnection Connection = Connection
+  type PrimaryConnection Connection = Connection
   type ReplicaConnection Connection = Connection
   type ReplicaIdentifier Connection = InstanceName Connection
 
   runWriteAny b m = runWrite b () m
-  runWrite b () m = withResource' (multiPoolMaster b) $ runReaderT m
+  runWrite b () m = withResource' (multiPoolPrimary b) $ runReaderT m
 
-  runReadMaster b () m = runReadAnyMaster b m
-  runReadAnyMaster b m = withResource' (multiPoolMaster b) $ runReaderT m
+  runReadPrimary b () m = runReadAnyPrimary b m
+  runReadAnyPrimary b m = withResource' (multiPoolPrimary b) $ runReaderT m
   runReadAny b m = do
     mident <- liftIO $ multiPoolAnyReplicaSelector b b
     case mident of
-      Nothing -> runReadAnyMaster b m
+      Nothing -> runReadAnyPrimary b m
       Just ident -> runRead b ident m
   runRead b ident m = case HM.lookup ident (multiPoolReplica b) of
     Nothing -> throw (InstanceDoesNotExist ident)
     Just repl -> withResource' repl $ runReaderT m
+
+  takePrimary b () = liftIO $ takeResource $ multiPoolPrimary b
+  putPrimary _ l c = liftIO $ putResource l c
+
+  takeReplica b ident = case HM.lookup ident (multiPoolReplica b) of
+    Nothing -> throw (InstanceDoesNotExist ident)
+    Just repl -> liftIO $ takeResource repl
+  putReplica _ l c = liftIO $ putResource l c