diff --git a/lib/jsonapi/filtering.rb b/lib/jsonapi/filtering.rb
index 70d47db..d09a619 100644
--- a/lib/jsonapi/filtering.rb
+++ b/lib/jsonapi/filtering.rb
@@ -62,7 +62,7 @@ def jsonapi_filter_params(allowed_fields)
           to_filter = to_filter.split(',')
         end
 
-        if predicates.any? && (field_names - allowed_fields).empty?
+        if (field_names - allowed_fields).empty?
           filtered[requested_field] = to_filter
         end
       end
diff --git a/spec/dummy.rb b/spec/dummy.rb
index 6f0c434..c8d6680 100644
--- a/spec/dummy.rb
+++ b/spec/dummy.rb
@@ -31,6 +31,12 @@
 
 class User < ActiveRecord::Base
   has_many :notes
+
+  scope :created_before, ->(date) { where('created_at < ?', date) }
+
+  def self.ransackable_scopes(_auth_object = nil)
+    [:created_before]
+  end
 end
 
 class Note < ActiveRecord::Base
@@ -83,7 +89,7 @@ class UsersController < ActionController::Base
   def index
     allowed_fields = [
       :first_name, :last_name, :created_at,
-      :notes_created_at, :notes_quantity
+      :notes_created_at, :notes_quantity, :created_before
     ]
     options = { sort_with_expressions: true }
 
diff --git a/spec/filtering_spec.rb b/spec/filtering_spec.rb
index f3bd80a..a078de0 100644
--- a/spec/filtering_spec.rb
+++ b/spec/filtering_spec.rb
@@ -96,6 +96,29 @@
           expect(response_json['data'][0]).to have_id(second_user.id.to_s)
         end
       end
+
+      context 'returns users filtered by scope' do
+        let(:params) do
+          third_user.update(created_at: '2013-01-01')
+
+          {
+            filter: { created_before: '2013-02-01' }
+          }
+        end
+
+        fit 'ensures ransack scopes are working properly' do
+          ransack = User.ransack({ created_before: '2013-02-01' })
+          expected_sql = 'SELECT "users".* FROM "users" WHERE '\
+                         '(created_at < \'2013-02-01\')'
+          expect(ransack.result.to_sql).to eq(expected_sql)
+        end
+
+        fit 'should return only' do
+          expect(response).to have_http_status(:ok)
+          expect(response_json['data'].size).to eq(1)
+          expect(response_json['data'][0]).to have_id(third_user.id.to_s)
+        end
+      end
     end
   end
 end