diff --git a/activerecord/lib/active_record/validations/uniqueness.rb b/activerecord/lib/active_record/validations/uniqueness.rb
index 4dbe475331..255063e951 100644
--- a/activerecord/lib/active_record/validations/uniqueness.rb
+++ b/activerecord/lib/active_record/validations/uniqueness.rb
@@ -65,6 +65,7 @@ module ActiveRecord
           value = value.to_s[0, column.limit]
         end
 
+        value = Arel::Nodes::Quoted.new(value)
         if !options[:case_sensitive] && value && column.text?
           # will use SQL LOWER function before comparison, unless it detects a case insensitive collation
           klass.connection.case_insensitive_comparison(table, attribute, column, value)