diff --git a/lib/ransack/adapters/active_record/context.rb b/lib/ransack/adapters/active_record/context.rb
index 3fbd8356a..1de1adf7f 100644
--- a/lib/ransack/adapters/active_record/context.rb
+++ b/lib/ransack/adapters/active_record/context.rb
@@ -44,9 +44,9 @@ def evaluate(search, opts = {})
               else
                 case Ransack.options[:postgres_fields_sort_option]
                 when :nulls_first
-                  scope_or_sort = scope_or_sort.direction == :asc ? "#{scope_or_sort.to_sql} NULLS FIRST" : "#{scope_or_sort.to_sql} NULLS LAST"
+                  scope_or_sort = Arel.sql(scope_or_sort.direction == :asc ? "#{scope_or_sort.to_sql} NULLS FIRST" : "#{scope_or_sort.to_sql} NULLS LAST")
                 when :nulls_last
-                  scope_or_sort = scope_or_sort.direction == :asc ? "#{scope_or_sort.to_sql} NULLS LAST" : "#{scope_or_sort.to_sql} NULLS FIRST"
+                  scope_or_sort = Arel.sql(scope_or_sort.direction == :asc ? "#{scope_or_sort.to_sql} NULLS LAST" : "#{scope_or_sort.to_sql} NULLS FIRST")
                 end
 
                 relation = relation.order(scope_or_sort)
diff --git a/spec/ransack/adapters/active_record/base_spec.rb b/spec/ransack/adapters/active_record/base_spec.rb
index 851819640..aa07388b3 100644
--- a/spec/ransack/adapters/active_record/base_spec.rb
+++ b/spec/ransack/adapters/active_record/base_spec.rb
@@ -585,6 +585,13 @@ def self.simple_escaping?
             )
           end
 
+          it 'shouldn\'t trigger a deprecation warning when fields_sort_options is set' do
+            Ransack.configure { |c| c.postgres_fields_sort_option = :nulls_first }
+            search = Person.ransack(sorts: ['name_case_insensitive desc'])
+            expect { search.result.first }.to_not output.to_stderr
+            Ransack.configure { |c| c.postgres_fields_sort_option = nil }
+          end
+
           context 'case insensitive sorting' do
             it 'allows sort by desc' do
               search = Person.ransack(sorts: ['name_case_insensitive desc'])