diff --git a/include/ruby/thread_native.h b/include/ruby/thread_native.h
index 8e500c5a13..92405a6e88 100644
--- a/include/ruby/thread_native.h
+++ b/include/ruby/thread_native.h
@@ -16,7 +16,7 @@
  * This file contains wrapper APIs for native thread primitives
  * which Ruby interpreter uses.
  *
- * Now, we only suppors pthread and Windows threads.
+ * Now, we only support pthread and Windows threads.
  *
  * If you want to use Ruby's Mutex and so on to synchronize Ruby Threads,
  * please use Mutex directly.