1 files changed, 6 insertions, 2 deletions
diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index 8c63070084..ae1b7930af 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -436,8 +436,12 @@ module Arel
       end
 
       def visit_Arel_Nodes_Grouping o, collector
-        collector << "("
-        visit(o.expr, collector) << ")"
+        if o.expr.is_a? Nodes::Grouping
+          visit(o.expr, collector)
+        else
+          collector << "("
+          visit(o.expr, collector) << ")"
+        end
       end
 
       def visit_Arel_SelectManager o, collector