diff --git a/library/PostgresqlSyntax/Ast.hs b/library/PostgresqlSyntax/Ast.hs
--- a/library/PostgresqlSyntax/Ast.hs
+++ b/library/PostgresqlSyntax/Ast.hs
@@ -764,8 +764,16 @@
 -- | ONLY '(' qualified_name ')'
 -- @
 data RelationExpr
-  = SimpleRelationExpr QualifiedName Bool
-  | OnlyRelationExpr QualifiedName Bool
+  = SimpleRelationExpr
+      QualifiedName
+      -- ^ Name.
+      Bool
+      -- ^ Is asterisk present?
+  | OnlyRelationExpr
+      QualifiedName
+      -- ^ Name.
+      Bool
+      -- ^ Are parentheses present?
   deriving (Show, Generic, Eq, Ord)
 
 -- |
diff --git a/postgresql-syntax.cabal b/postgresql-syntax.cabal
--- a/postgresql-syntax.cabal
+++ b/postgresql-syntax.cabal
@@ -1,5 +1,5 @@
 name: postgresql-syntax
-version: 0.4.0.1
+version: 0.4.0.2
 category: Database, PostgreSQL, Parsing
 synopsis: PostgreSQL AST parsing and rendering
 description: