diff --git a/relational-query.cabal b/relational-query.cabal
--- a/relational-query.cabal
+++ b/relational-query.cabal
@@ -1,5 +1,5 @@
 name:                relational-query
-version:             0.0.1.0
+version:             0.0.1.1
 synopsis:            Typeful, Modular, Relational, algebraic query engine
 description:         This package contiains typeful relation structure and
                      relational-algebraic query building DSL which can
diff --git a/src/Database/Relational/Query.hs b/src/Database/Relational/Query.hs
--- a/src/Database/Relational/Query.hs
+++ b/src/Database/Relational/Query.hs
@@ -78,4 +78,6 @@
 import Database.Relational.Query.Effect
 import Database.Relational.Query.Derives
 
+import Database.Record.Instances ()
+
 {-# ANN module "HLint: ignore Use import/export shortcut" #-}
diff --git a/src/Database/Relational/Query/Sub.hs b/src/Database/Relational/Query/Sub.hs
--- a/src/Database/Relational/Query/Sub.hs
+++ b/src/Database/Relational/Query/Sub.hs
@@ -50,7 +50,7 @@
 import Database.Relational.Query.Component
   (ColumnSQL, columnSQL', showsColumnSQL,
    Config (productUnitSupport), ProductUnitSupport (PUSupported, PUNotSupported),
-   Duplication, showsDuplication, QueryRestriction, composeWhere, composeHaving,
+   Duplication (..), showsDuplication, QueryRestriction, composeWhere, composeHaving,
    AggregateElem, composeGroupBy, OrderingTerms, composeOrderBy)
 import Database.Relational.Query.Table (Table, (!))
 import qualified Database.Relational.Query.Table as Table
@@ -63,12 +63,17 @@
 
 newtype BinOp = BinOp (SetOp, Duplication) deriving Show
 
-showsSetOp :: SetOp -> StringSQL
-showsSetOp =  d  where
+showsSetOp' :: SetOp -> StringSQL
+showsSetOp' =  d  where
   d Union     = UNION
   d Except    = EXCEPT
   d Intersect = INTERSECT
 
+showsSetOp :: SetOp -> Duplication -> StringSQL
+showsSetOp op dup0 = showsSetOp' op <> mayDup dup0  where
+  mayDup dup@All  = showsDuplication dup
+  mayDup Distinct = mempty
+
 -- | Sub-query type
 data SubQuery = Table Table.Untyped
               | Flat Config
@@ -165,7 +170,7 @@
 toSQLs =  d  where
   d (Table u)               = (stringSQL $ Table.name' u, fromTableToSQL u)
   d (Bin (BinOp (op, da)) l r) = (SQL.paren q, q)  where
-    q = mconcat [normalizedSQL l, showsSetOp op, showsDuplication da, normalizedSQL r]
+    q = mconcat [normalizedSQL l, showsSetOp op da, normalizedSQL r]
   d (Flat cf up da pd rs od)   = (SQL.paren q, q)  where
     q = selectPrefixSQL up da <> showsJoinProduct (productUnitSupport cf) pd <> composeWhere rs
         <> composeOrderBy od
diff --git a/src/Database/Relational/Query/TH.hs b/src/Database/Relational/Query/TH.hs
--- a/src/Database/Relational/Query/TH.hs
+++ b/src/Database/Relational/Query/TH.hs
@@ -78,7 +78,6 @@
    defineRecordTypeDefault,
    defineHasColumnConstraintInstance)
 import qualified Database.Record.TH as Record
-import Database.Record.Instances ()
 
 import Database.Relational.Query
   (Table, Pi, Relation, Config (normalizedTableName), ProductConstructor (..),