diff --git a/text_to_sql_query.rb b/text_to_sql_query.rb
index bd40ba5..ac1e085 100644
--- a/text_to_sql_query.rb
+++ b/text_to_sql_query.rb
@@ -74,6 +74,6 @@ class TextToSqlQuery
     second_operand_expression = second_operand.first
     second_operand_params = second_operand[1..]
 
-    ["#{first_operand_expression} #{operator.to_s} #{second_operand_expression}"] + first_operand_params + second_operand_params
+    ["(#{first_operand_expression} #{operator.to_s} #{second_operand_expression})"] + first_operand_params + second_operand_params
   end
 end
\ No newline at end of file