--- Libc/Libc-583/pthreads/pthread_mutex_destroy.3
+++ Libc/Libc-498/pthreads/pthread_mutex_destroy.3
@@ -55,7 +55,7 @@
 .Bl -tag -width Er
 .It Bq Er EBUSY
 .Fa Mutex
-is locked by a thread.
+is locked by another thread.
 .It Bq Er EINVAL
 The value specified by
 .Fa mutex