diff --git a/lib/carmen/rails/action_view/form_helper.rb b/lib/carmen/rails/action_view/form_helper.rb
index ba9daf8..d5f5510 100644
--- a/lib/carmen/rails/action_view/form_helper.rb
+++ b/lib/carmen/rails/action_view/form_helper.rb
@@ -94,6 +94,11 @@ def region_options_for_select(regions, selected=nil, options={})
           unless priority_regions.empty?
             region_options += options_for_select(priority_regions, selected)
             region_options += "<option disabled>-------------</option>"
+
+            # If a priority region is selected, don't select it again in the main list.
+            # This prevents some browsers from selecting the second occurance of this region,
+            # which makes it difficult to select an alternative priority region.
+            selected = nil if priority_region_codes.include?(selected)
           end
         end
 
diff --git a/test/carmen/action_view/helpers/form_helper_test.rb b/test/carmen/action_view/helpers/form_helper_test.rb
index 1794b44..5b5fd29 100644
--- a/test/carmen/action_view/helpers/form_helper_test.rb
+++ b/test/carmen/action_view/helpers/form_helper_test.rb
@@ -101,6 +101,23 @@ def test_priority_country_select_deprecated_api
     assert_equal_markup(expected, html)
   end
 
+  def test_country_select_selected_priority_region_not_selected_twice
+    @object.country_code = 'ES'
+
+    html = country_select(@object, :country_code, :priority => ['ES'])
+    expected = <<-HTML
+      <select id="object_country_code" name="object[country_code]">
+        <option value="ES" selected="selected">Eastasia</option>
+        <option disabled>-------------</option>
+        <option value="ES">Eastasia</option>
+        <option value="EU">Eurasia</option>
+        <option value="OC">Oceania</option>
+      </select>
+    HTML
+
+    assert_equal_markup(expected, html)
+  end
+
   def test_basic_subregion_select
     oceania = Carmen::Country.coded('OC')
     expected = <<-HTML
diff --git a/test/test_helper.rb b/test/test_helper.rb
index f4918b2..bd63c69 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -30,6 +30,12 @@ def assert_equal_markup(expected, actual, message=nil)
   private
 
   def clean_markup(markup)
+    clean_whitespace(markup).gsub(/( [a-zA-Z_]*="[^"]*")+/) do |match|
+      ' ' + match.strip!.split(' ').sort.join(' ')
+    end
+  end
+
+  def clean_whitespace(markup)
     markup.
       gsub(/\s+/, ' ').    # cleanup whitespace
       gsub(/>\s/, '>').    # kill space after tags