diff --git a/activesupport/lib/active_support/parameter_filter.rb b/activesupport/lib/active_support/parameter_filter.rb
index 8e5595babf..e1cd7c46c1 100644
--- a/activesupport/lib/active_support/parameter_filter.rb
+++ b/activesupport/lib/active_support/parameter_filter.rb
@@ -109,7 +109,12 @@ module ActiveSupport
         elsif value.is_a?(Hash)
           value = call(value, parents, original_params)
         elsif value.is_a?(Array)
-          value = value.map { |v| v.is_a?(Hash) ? call(v, parents, original_params) : v }
+          # If we don't pop the current parent it will be duplicated as we
+          # process each array value.
+          parents.pop if deep_regexps
+          value = value.map { |v| value_for_key(key, v, parents, original_params) }
+          # Restore the parent stack after processing the array.
+          parents.push(key) if deep_regexps
         elsif blocks.any?
           key = key.dup if key.duplicable?
           value = value.dup if value.duplicable?
diff --git a/activesupport/test/parameter_filter_test.rb b/activesupport/test/parameter_filter_test.rb
index d2dc71061d..e680a22479 100644
--- a/activesupport/test/parameter_filter_test.rb
+++ b/activesupport/test/parameter_filter_test.rb
@@ -28,10 +28,17 @@ class ParameterFilterTest < ActiveSupport::TestCase
         value.replace("world!") if original_params["barg"]["blah"] == "bar" && key == "hello"
       }
 
+      filter_words << lambda { |key, value|
+        value.upcase! if key == "array_elements"
+      }
+
       parameter_filter = ActiveSupport::ParameterFilter.new(filter_words)
       before_filter["barg"] = { :bargain => "gain", "blah" => "bar", "bar" => { "bargain" => { "blah" => "foo", "hello" => "world" } } }
       after_filter["barg"]  = { :bargain => "niag", "blah" => "[FILTERED]", "bar" => { "bargain" => { "blah" => "[FILTERED]", "hello" => "world!" } } }
 
+      before_filter["array_elements"] = %w(element1 element2)
+      after_filter["array_elements"] = %w(ELEMENT1 ELEMENT2)
+
       assert_equal after_filter, parameter_filter.filter(before_filter)
     end
   end