diff --git a/os/rt/include/chschd.h b/os/rt/include/chschd.h
index 93b72ec31..18412ccc1 100644
--- a/os/rt/include/chschd.h
+++ b/os/rt/include/chschd.h
@@ -76,7 +76,7 @@
 #define CH_STATE_SNDMSGQ    (tstate_t)12     /**< @brief Sending a message,
                                                   in queue.                 */
 #define CH_STATE_SNDMSG     (tstate_t)13     /**< @brief Sent a message,
-                                                  waiting answer.          */
+                                                  waiting answer.           */
 #define CH_STATE_WTMSG      (tstate_t)14     /**< @brief Waiting for a
                                                   message.                  */
 #define CH_STATE_FINAL      (tstate_t)15     /**< @brief Thread terminated. */