diff --git a/Python/thread_nt.h b/Python/thread_nt.h
index 74a6ee80298..d87f9614498 100644
--- a/Python/thread_nt.h
+++ b/Python/thread_nt.h
@@ -235,7 +235,7 @@ PyThread_exit_thread(void)
 }
 
 /*
- * Lock support. It has too be implemented as semaphores.
+ * Lock support. It has to be implemented as semaphores.
  * I [Dag] tried to implement it with mutex but I could find a way to
  * tell whether a thread already own the lock or not.
  */