diff --git a/test/ruby/test_exception.rb b/test/ruby/test_exception.rb
index a24f1ca05d..f3aea58c73 100644
--- a/test/ruby/test_exception.rb
+++ b/test/ruby/test_exception.rb
@@ -342,7 +342,7 @@ class TestException < Test::Unit::TestCase
   end
 
   def test_thread_signal_location
-    _, stderr, _ = EnvUtil.invoke_ruby("--disable-gems -d", <<-RUBY, false, true)
+    _, stderr, _ = EnvUtil.invoke_ruby(%w"--disable-gems -d", <<-RUBY, false, true)
 Thread.start do
   begin
     Process.kill(:INT, $$)