diff --git a/lib/geared_pagination/portions/portion_at_offset.rb b/lib/geared_pagination/portions/portion_at_offset.rb
index 338c55d..c5c5e99 100644
--- a/lib/geared_pagination/portions/portion_at_offset.rb
+++ b/lib/geared_pagination/portions/portion_at_offset.rb
@@ -17,7 +17,10 @@ def limit
     end
 
     def offset
-      (page_number - 1).times.sum { |index| ratios[index + 1] }
+      variable = [(page_number - 1), ratios.size - 1].min.times.sum { |index| ratios[index + 1] }
+      fixed = [page_number - ratios.size, 0].max * ratios.fixed
+
+      variable + fixed
     end
 
     def next_param(*)
diff --git a/lib/geared_pagination/ratios.rb b/lib/geared_pagination/ratios.rb
index 615b95f..5e48782 100644
--- a/lib/geared_pagination/ratios.rb
+++ b/lib/geared_pagination/ratios.rb
@@ -3,15 +3,23 @@ class Ratios
     DEFAULTS = [ 15, 30, 50, 100 ]
 
     def initialize(ratios = nil)
-      @ratios = Array(ratios || DEFAULTS)
+      @ratios = Array(ratios || DEFAULTS).map(&:to_i)
     end
 
     def [](page_number)
-      @ratios[page_number - 1] || @ratios.last
+      @ratios[page_number - 1] || fixed
     end
 
     def cache_key
       @ratios.join('-')
     end
+
+    def size
+      @ratios.size
+    end
+
+    def fixed
+      @ratios.last
+    end
   end
 end
diff --git a/test/controller_test.rb b/test/controller_test.rb
index 6280904..debdfc1 100644
--- a/test/controller_test.rb
+++ b/test/controller_test.rb
@@ -14,6 +14,9 @@ class GearedPagination::ControllerTest < ActionController::TestCase
     assert_equal etag_for("placeholder", "page/1:1-2"), response.etag
     etag_before_gearing_change = response.etag
 
+    get :index, params: { page: 2, per_page: [ 1, 2 ] }
+    assert_equal etag_for("placeholder", "page/2:1-2"), response.etag
+
     get :index, params: { page: 1, per_page: [ 1, 2 ] }
     assert_equal etag_before_gearing_change, response.etag
 
diff --git a/test/portion_at_offset_test.rb b/test/portion_at_offset_test.rb
index ae3f210..01134e6 100644
--- a/test/portion_at_offset_test.rb
+++ b/test/portion_at_offset_test.rb
@@ -7,6 +7,9 @@ class GearedPagination::PortionAtOffsetTest < ActiveSupport::TestCase
     assert_equal 0, GearedPagination::PortionAtOffset.new(page_number: 1).offset
     assert_equal GearedPagination::Ratios::DEFAULTS.first, GearedPagination::PortionAtOffset.new(page_number: 2).offset
     assert_equal GearedPagination::Ratios::DEFAULTS.first + GearedPagination::Ratios::DEFAULTS.second, GearedPagination::PortionAtOffset.new(page_number: 3).offset
+    assert_equal 4.times.sum { |index| GearedPagination::Ratios::DEFAULTS[index] || GearedPagination::Ratios::DEFAULTS.last }, GearedPagination::PortionAtOffset.new(page_number: 5).offset
+    assert_equal 5.times.sum { |index| GearedPagination::Ratios::DEFAULTS[index] || GearedPagination::Ratios::DEFAULTS.last }, GearedPagination::PortionAtOffset.new(page_number: 6).offset
+    assert_equal 9.times.sum { |index| GearedPagination::Ratios::DEFAULTS[index] || GearedPagination::Ratios::DEFAULTS.last }, GearedPagination::PortionAtOffset.new(page_number: 10).offset
   end
 
   test "limit" do