diff --git a/lib/cancan/rule.rb b/lib/cancan/rule.rb
index 44c14af..27355bd 100644
--- a/lib/cancan/rule.rb
+++ b/lib/cancan/rule.rb
@@ -111,7 +111,7 @@ module CanCan
                 else
                   !attribute.nil? && matches_conditions_hash?(attribute, value)
                 end
-              elsif value.kind_of?(Array) || value.kind_of?(Range)
+              elsif value.kind_of?(Enumerable)
                 value.include? attribute
               else
                 attribute == value
diff --git a/spec/cancan/ability_spec.rb b/spec/cancan/ability_spec.rb
index 48b6782..a99aea5 100644
--- a/spec/cancan/ability_spec.rb
+++ b/spec/cancan/ability_spec.rb
@@ -249,7 +249,15 @@ describe CanCan::Ability do
     @ability.can?(:read, 1..5).should be_true
     @ability.can?(:read, 4..6).should be_false
   end
-  
+
+  it "should accept a set as a condition value" do
+    mock(object_with_foo_2 = Object.new).foo { 2 }
+    mock(object_with_foo_3 = Object.new).foo { 3 }
+    @ability.can :read, Object, :foo => [1, 2, 5].to_set
+    @ability.can?(:read, object_with_foo_2).should be_true
+    @ability.can?(:read, object_with_foo_3).should be_false
+  end
+
   it "should not match subjects return nil for methods that must match nested a nested conditions hash" do
     mock(object_with_foo = Object.new).foo { :bar }
     @ability.can :read, Array, :first => { :foo => :bar }