diff --git a/relational-query/src/Database/Relational/Query/Monad/Trans/Join.hs b/relational-query/src/Database/Relational/Query/Monad/Trans/Join.hs
index 0c851366..8b027e2a 100644
--- a/relational-query/src/Database/Relational/Query/Monad/Trans/Join.hs
+++ b/relational-query/src/Database/Relational/Query/Monad/Trans/Join.hs
@@ -34,9 +34,9 @@ import Data.Maybe (fromMaybe)
 import Data.Monoid (Last (Last, getLast))
 
 import Database.Relational.Query.Internal.BaseSQL (Duplication (All))
-import Database.Relational.Query.Internal.Sub (NodeAttr (Just', Maybe), SubQuery, Qualified, JoinProduct, Projection)
 import Database.Relational.Query.Internal.Product (restrictProduct, growProduct)
 
+import Database.Relational.Query.Sub (NodeAttr (Just', Maybe), SubQuery, Qualified, JoinProduct, Projection)
 import Database.Relational.Query.Context (Flat)
 import Database.Relational.Query.Monad.Trans.JoinState
   (JoinContext, primeJoinContext, updateProduct, joinProduct)
diff --git a/relational-query/src/Database/Relational/Query/Relation.hs b/relational-query/src/Database/Relational/Query/Relation.hs
index 46a886d3..0e0d1a08 100644
--- a/relational-query/src/Database/Relational/Query/Relation.hs
+++ b/relational-query/src/Database/Relational/Query/Relation.hs
@@ -43,7 +43,6 @@ module Database.Relational.Query.Relation (
 import Control.Applicative ((<$>))
 
 import Database.Relational.Query.Internal.BaseSQL (Duplication (Distinct, All))
-import Database.Relational.Query.Internal.Sub (NodeAttr(Just', Maybe))
 
 import Database.Relational.Query.Context (Flat, Aggregated)
 import Database.Relational.Query.Monad.BaseType
@@ -58,7 +57,7 @@ import qualified Database.Relational.Query.Monad.Aggregate as Aggregate
 import Database.Relational.Query.Monad.Unique (QueryUnique, unsafeUniqueSubQuery)
 import qualified Database.Relational.Query.Monad.Unique as Unique
 import Database.Relational.Query.Table (Table, TableDerivable, derivedTable)
-import Database.Relational.Query.Sub (SubQuery)
+import Database.Relational.Query.Sub (SubQuery, NodeAttr(Just', Maybe))
 import qualified Database.Relational.Query.Sub as SubQuery
 import Database.Relational.Query.Scalar (ScalarDegree)
 import Database.Relational.Query.Pi (Pi)
diff --git a/relational-query/src/Database/Relational/Query/Sub.hs b/relational-query/src/Database/Relational/Query/Sub.hs
index 87fd8d10..4aa3b1c2 100644
--- a/relational-query/src/Database/Relational/Query/Sub.hs
+++ b/relational-query/src/Database/Relational/Query/Sub.hs
@@ -40,7 +40,7 @@ module Database.Relational.Query.Sub (
   widthOfUntypedProjection, columnsOfUntypedProjection,
 
   -- * Product of sub-queries
-  JoinProduct, NodeAttr,
+  JoinProduct, NodeAttr (..),
   nodeTree,
   ProductBuilder,