Index: lib/libc/sys/mmap.2
===================================================================
--- lib/libc/sys/mmap.2
+++ lib/libc/sys/mmap.2
@@ -431,7 +431,7 @@
 An invalid value was passed in the
 .Fa prot
 argument.
-.It Bq Er EINVAL
+.It Bq Er ENOTSUP
 The
 .Fa prot
 argument contains permissions which are not a subset of the specified
Index: lib/libc/sys/mprotect.2
===================================================================
--- lib/libc/sys/mprotect.2
+++ lib/libc/sys/mprotect.2
@@ -98,7 +98,7 @@
 The
 .Fa prot
 argument contains unhandled bits.
-.It Bq Er EINVAL
+.It Bq Er ENOTSUP
 The
 .Fa prot
 argument contains permissions which are not a subset of the specified
Index: sys/vm/vm_mmap.c
===================================================================
--- sys/vm/vm_mmap.c
+++ sys/vm/vm_mmap.c
@@ -225,7 +225,7 @@
 	max_prot = PROT_MAX_EXTRACT(prot);
 	prot = PROT_EXTRACT(prot);
 	if (max_prot != 0 && (max_prot & prot) != prot)
-		return (EINVAL);
+		return (ENOTSUP);
 
 	p = td->td_proc;
 
@@ -668,7 +668,7 @@
 	vm_error = KERN_SUCCESS;
 	if (max_prot != 0) {
 		if ((max_prot & prot) != prot)
-			return (EINVAL);
+			return (ENOTSUP);
 		vm_error = vm_map_protect(&td->td_proc->p_vmspace->vm_map,
 		    addr, addr + size, max_prot, TRUE);
 	}