diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # CHANGELOG
 
+## 3.2.0
+### Changed
+* Change interface of `deriveEntity`: now you can state the schema of
+  table of entity. (by @4e6)
+
 ## 3.1.0
 ### Changed
 * Support for inflections-0.3 (fixed buildability). Tested with LTS 8.5
diff --git a/postgresql-query.cabal b/postgresql-query.cabal
--- a/postgresql-query.cabal
+++ b/postgresql-query.cabal
@@ -1,5 +1,5 @@
 name:                postgresql-query
-version:             3.1.0
+version:             3.2.0
 
 synopsis: Sql interpolating quasiquote plus some kind of primitive ORM
           using it
diff --git a/src/Database/PostgreSQL/Query/TH.hs b/src/Database/PostgreSQL/Query/TH.hs
--- a/src/Database/PostgreSQL/Query/TH.hs
+++ b/src/Database/PostgreSQL/Query/TH.hs
@@ -25,8 +25,8 @@
 
 $(deriveEverything
   def { eoIdType        = ''Id
-      , eoTableName     = toUnderscore
-      , eoColumnNames   = toUnderscore . drop 1
+      , eoTableName     = textFN . toUnderscore'
+      , eoColumnNames   = textFN . toUnderscore' . drop 1
       , eoDeriveClasses =
         [''Show, ''Read, ''Ord, ''Eq
         , ''FromField, ''ToField, ''PathPiece]
diff --git a/src/Database/PostgreSQL/Query/TH/Entity.hs b/src/Database/PostgreSQL/Query/TH/Entity.hs
--- a/src/Database/PostgreSQL/Query/TH/Entity.hs
+++ b/src/Database/PostgreSQL/Query/TH/Entity.hs
@@ -7,10 +7,10 @@
 
 import Data.Default
 import Data.String
-import Data.Text (pack, unpack)
+import Data.Text (Text, pack, unpack)
 import Database.PostgreSQL.Query.Entity.Class
 import Database.PostgreSQL.Query.TH.Common
-import Database.PostgreSQL.Query.Types ( FN(..) )
+import Database.PostgreSQL.Query.Types ( FN(..), textFN )
 import Database.PostgreSQL.Simple.FromField
 import Database.PostgreSQL.Simple.ToField
 import GHC.Generics (Generic)
@@ -24,37 +24,31 @@
 
 -- | Options for deriving `Entity`
 data EntityOptions = EntityOptions
-    { eoTableName      :: String -> String -- ^ Type name to table name converter
-    , eoColumnNames    :: String -> String -- ^ Record field to column name converter
-    , eoDeriveClasses  :: [Name]           -- ^ Typeclasses to derive for Id
-    , eoIdType         :: Name             -- ^ Base type for Id
+    { eoTableName      :: Text -> FN -- ^ Type name to table name converter
+    , eoColumnNames    :: Text -> FN -- ^ Record field to column name converter
+    , eoDeriveClasses  :: [Name]     -- ^ Typeclasses to derive for Id
+    , eoIdType         :: Name       -- ^ Base type for Id
     } deriving (Generic)
 
 #if !MIN_VERSION_inflections(0,3,0)
-instance Default EntityOptions where
-  def = EntityOptions
-        { eoTableName     = toUnderscore
-        , eoColumnNames   = toUnderscore
-        , eoDeriveClasses = [ ''Ord, ''Eq, ''Show
-                            , ''FromField, ''ToField ]
-        , eoIdType        = ''Integer
-        }
+toUnderscore' :: Text -> Text
+toUnderscore' = pack . toUnderscore . unpack
 #else
+toUnderscore' :: Text -> Text
+toUnderscore' = either error' id . toUnderscore
+  where
+    error' er = error $ "toUnderscore: " ++ show er
+#endif
+
 instance Default EntityOptions where
   def = EntityOptions
-        { eoTableName     = toUnderscore'
-        , eoColumnNames   = toUnderscore'
+        { eoTableName     = textFN . toUnderscore'
+        , eoColumnNames   = textFN . toUnderscore'
         , eoDeriveClasses = [ ''Ord, ''Eq, ''Show
                             , ''FromField, ''ToField ]
         , eoIdType        = ''Integer
         }
 
-toUnderscore' :: String -> String
-toUnderscore' s = case toUnderscore $ pack s of
-  Left er -> error $ "toUnderscore: " ++ show er
-  Right a -> unpack a
-#endif
-
 {- | Derives instance for 'Entity' using type name and field names. Also
 generates type synonim for ID. E.g. code like this:
 
@@ -67,8 +61,8 @@
 
 $(deriveEntity
   def { eoIdType        = ''Id
-      , eoTableName     = toUnderscore
-      , eoColumnNames   = toUnderscore . drop 1
+      , eoTableName     = textFN . toUnderscore'
+      , eoColumnNames   = textFN . toUnderscore' . drop 1
       , eoDeriveClasses =
         [''Show, ''Read, ''Ord, ''Eq
         , ''FromField, ''ToField, ''PathPiece]
@@ -115,8 +109,8 @@
         iddec = NewtypeInstD [] entityIdName [ConT tname]
                 idcon (eoDeriveClasses opts)
 #endif
-        tblName = fromString $ eoTableName opts tnames
-        fldNames = map (fromString . eoColumnNames opts . nameBase)
+        tblName = eoTableName opts $ pack tnames
+        fldNames = map (eoColumnNames opts . pack . nameBase)
                    $ cFieldNames tcon
     VarE ntableName  <- [e|tableName|]
     VarE nfieldNames <- [e|fieldNames|]