diff --git a/lib/librt/Makefile b/lib/librt/Makefile
index c755bb123c73..1189636d0416 100644
--- a/lib/librt/Makefile
+++ b/lib/librt/Makefile
@@ -1,27 +1,29 @@
 SHLIBDIR?=/lib
 
 .include <src.opts.mk>
 
 PACKAGE=clibs
 LIB=rt
 SHLIB_MAJOR= 1
 CFLAGS+=-I${SRCTOP}/lib/libc/include -I${.CURDIR}
 .ifndef NO_THREAD_STACK_UNWIND
 CFLAGS+=-fexceptions
 .endif
 CFLAGS+=-Wall
 LIBADD=	pthread
 
 WARNS?=	2
 
 SRCS+= aio.c mq.c sigev_thread.c timer.c
 
 PRECIOUSLIB=
 
 VERSION_DEF=${SRCTOP}/lib/libc/Versions.def
 SYMBOL_MAPS=${.CURDIR}/Symbol.map
 
 HAS_TESTS=
 SUBDIR.${MK_TESTS}+= tests
 
+MAN= mq_getfd_np.3
+
 .include <bsd.lib.mk>
diff --git a/lib/librt/mq_getfd_np.3 b/lib/librt/mq_getfd_np.3
new file mode 100644
index 000000000000..44c29fbdbf73
--- /dev/null
+++ b/lib/librt/mq_getfd_np.3
@@ -0,0 +1,57 @@
+.\"
+.\" Copyright (c) 2024 Rick Parrish <unitrunker@unitrunker.net>
+.\"
+.\" SPDX-License-Identifier: BSD-2-Clause
+.\"
+.Dd December 18, 2025
+.Dt MQ_GETFD_NP 3
+.Os
+.Sh NAME
+.Nm mq_getfd_np
+.Nd get a file descriptor for an open message queue descriptor
+.Sh SYNOPSIS
+.Lb librt
+.In mqueue.h
+.Ft int
+.Fn mq_getfd_np "mqd_t mqd"
+.Sh DESCRIPTION
+The
+.Nm
+function retrieves the underlying file descriptor
+from the given message queue descriptor returned from
+.Xr mq_open 2 .
+The file descriptor is used by other functions
+to refer to that message queue.
+The
+.Fa mqd
+argument must be an open message queue descriptor.
+.Sh IMPLEMENTATION NOTES
+.Fx
+implements retrieval or alteration of message queue attributes
+based on the file descriptor.
+The open file descriptor is copied into a child after
+.Xr fork 2 .
+The
+.Xr fstat 2 ,
+.Xr fchmod 2 ,
+and
+.Xr fchown 2
+system calls are supported for the file descriptor.
+.Pp
+The file descriptor is safe to use so long as
+the message queue descriptor remains open.
+.Sh RETURN VALUES
+Upon successful completion, the function returns a file descriptor.
+.Sh ERRORS
+The
+.Nm
+function does not return any errors.
+.Sh SEE ALSO
+.Xr mq_close 2 ,
+.Xr mq_open 2 ,
+.Xr mqueuefs 4
+.Sh HISTORY
+Support for the
+.Nm
+function first appeared in
+.Fx 11.0 .