diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index be8b672fa7..8bd2a4530b 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -1501,7 +1501,9 @@ module ActiveRecord #:nodoc:
       # Interpolate custom sql string in instance context.
       # Optional record argument is meant for custom insert_sql.
       def interpolate_sql(sql, record = nil)
-        instance_eval("%(#{sql})")
+        # Parens in the sql in, e.g., subselects, cause a parse error, so
+        # escape them.
+        instance_eval("%@#{sql.gsub('@', '\@')}@")
       end
 
       # Initializes the attributes array with keys matching the columns from the linked table and
diff --git a/activerecord/test/base_test.rb b/activerecord/test/base_test.rb
index c7e795c0e6..9b5ce8a8ce 100755
--- a/activerecord/test/base_test.rb
+++ b/activerecord/test/base_test.rb
@@ -1018,6 +1018,12 @@ class BasicsTest < Test::Unit::TestCase
      assert_equal    firm.clients.collect{ |x| x.name }.sort, clients.collect{ |x| x.name }.sort
   end
 
+  def test_interpolate_sql
+    assert_nothing_raised { Category.new.send(:interpolate_sql, 'foo@bar') }
+    assert_nothing_raised { Category.new.send(:interpolate_sql, 'foo bar) baz') }
+    assert_nothing_raised { Category.new.send(:interpolate_sql, 'foo bar} baz') }
+  end
+
   private
 
     def assert_readers(model, exceptions)