--- Libc/Libc-583/pthreads/pthread_mutex_unlock.3
+++ Libc/Libc-498/pthreads/pthread_mutex_unlock.3
@@ -46,13 +46,6 @@
 .Fn pthread_mutex_unlock
 function unlocks
 .Fa mutex .
-.Pp
-Calling
-.Fn pthread_mutex_unlock
-with a
-.Fa mutex
-that the calling thread does not hold will result 
-in undefined behavior.
 .Sh RETURN VALUES
 If successful,
 .Fn pthread_mutex_unlock