diff --git a/relational-query/src/Database/Relational/Query/Component.hs b/relational-query/src/Database/Relational/Query/Component.hs
index 49df98ec..00627489 100644
--- a/relational-query/src/Database/Relational/Query/Component.hs
+++ b/relational-query/src/Database/Relational/Query/Component.hs
@@ -223,6 +223,7 @@ composeValues :: [Assignment] -> StringSQL
 composeValues = BaseSQL.composeValues
 
 
+{-# DEPRECATED composeOver "prepare to drop public interface." #-}
 -- | Compose /OVER (PARTITION BY ... )/ clause.
 composeOver :: [AggregateColumnRef] -> OrderingTerms -> StringSQL
 composeOver pts ots =
diff --git a/relational-query/src/Database/Relational/Query/Monad/Aggregate.hs b/relational-query/src/Database/Relational/Query/Monad/Aggregate.hs
index 5948b405..778f5476 100644
--- a/relational-query/src/Database/Relational/Query/Monad/Aggregate.hs
+++ b/relational-query/src/Database/Relational/Query/Monad/Aggregate.hs
@@ -29,13 +29,16 @@ module Database.Relational.Query.Monad.Aggregate (
 import Data.Functor.Identity (Identity (runIdentity))
 import Data.Monoid ((<>))
 
+import Language.SQL.Keyword (Keyword(..))
+import qualified Language.SQL.Keyword as SQL
+
 import Database.Relational.Query.Internal.SQL (showsColumnSQL)
+import Database.Relational.Query.Internal.BaseSQL (Duplication, OrderingTerm, composeOrderBy)
+import Database.Relational.Query.Internal.GroupingSQL (AggregateColumnRef, AggregateElem, composePartitionBy)
 
 import Database.Relational.Query.Context (Flat, Aggregated, OverWindow)
 import Database.Relational.Query.Projection (Projection)
 import qualified Database.Relational.Query.Projection as Projection
-import Database.Relational.Query.Component
-  (AggregateColumnRef, Duplication, OrderingTerm, AggregateElem, composeOver)
 import Database.Relational.Query.Sub (SubQuery, QueryRestriction, JoinProduct, aggregatedSubQuery)
 import qualified Database.Relational.Query.Sub as SubQuery
 import Database.Relational.Query.Projectable (PlaceHolders, SqlProjectable)
@@ -94,7 +97,7 @@ over :: SqlProjectable (Projection c)
      -> Projection c a
 wp `over` win =
   Projection.unsafeFromSqlTerms
-  [ showsColumnSQL c <> composeOver pt ot
+  [ showsColumnSQL c <> OVER <> SQL.paren (composePartitionBy pt <> composeOrderBy ot)
   | c <- Projection.columns wp
   ]  where (((), ot), pt) = extractWindow win