diff --git a/spec/models/guard_arguments_check.rb b/spec/models/guard_arguments_check.rb
new file mode 100644
index 0000000..25d3423
--- /dev/null
+++ b/spec/models/guard_arguments_check.rb
@@ -0,0 +1,17 @@
+class GuardArgumentsCheck
+  include AASM
+
+  aasm do
+    state :new, :reviewed, :finalized
+
+    event :mark_as_reviewed,
+          :guard => proc { |*args| arguments_list(*args) } do
+      transitions :from => :new, :to => :reviewed
+    end
+  end
+
+  def arguments_list(arg1, arg2)
+    return false unless arg1.nil?
+    true
+  end
+end
diff --git a/spec/unit/guard_arguments_check_spec.rb b/spec/unit/guard_arguments_check_spec.rb
new file mode 100644
index 0000000..6ee6a5d
--- /dev/null
+++ b/spec/unit/guard_arguments_check_spec.rb
@@ -0,0 +1,9 @@
+require 'spec_helper'
+
+describe "nil as first argument" do
+  let(:guard) { GuardArgumentsCheck.new }
+
+  it 'does not raise errors' do
+    expect { guard.mark_as_reviewed(nil, 'second arg') }.not_to raise_error
+  end
+end