diff --git a/test/ruby/test_proc.rb b/test/ruby/test_proc.rb
index 728e2b7987..6914089b9d 100644
--- a/test/ruby/test_proc.rb
+++ b/test/ruby/test_proc.rb
@@ -579,7 +579,7 @@ class TestProc < Test::Unit::TestCase
     assert_equal [1, 2, 3], pr.call([1,2,3,4,5,6])
   end
 
-  def test_proc_args_opt_signle
+  def test_proc_args_opt_single
     bug7621 = '[ruby-dev:46801]'
     pr = proc {|a=:a|
       a