diff --git a/lib/libc/gen/psignal.3 b/lib/libc/gen/psignal.3
index 098b7b02a9b9..bf6a99b4b113 100644
--- a/lib/libc/gen/psignal.3
+++ b/lib/libc/gen/psignal.3
@@ -1,178 +1,185 @@
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 .\"
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 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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-.Dd May 10, 2025
+.Dd September 23, 2025
 .Dt PSIGNAL 3
 .Os
 .Sh NAME
 .Nm psignal ,
 .Nm psiginfo ,
 .Nm strsignal ,
 .Nm sys_siglist ,
 .Nm sys_signame ,
 .Nm sig2str ,
 .Nm str2sig
 .Nd system signal messages
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
 .In signal.h
 .Ft void
 .Fn psignal "int sig" "const char *s"
 .Ft void
 .Fn psiginfo "const siginfo_t *si" "const char *s"
 .Vt extern const char * const sys_siglist[] ;
 .Vt extern const char * const sys_signame[] ;
 .In string.h
 .Ft "char *"
 .Fn strsignal "int sig"
 .Ft int
 .Fn sig2str "int signum" "char *str"
 .Ft int
 .Fn str2sig "char *str" "int *pnum"
 .Sh DESCRIPTION
 The
 .Fn psignal
 and
 .Fn strsignal
 functions locate the descriptive message
 string for a signal number.
 .Pp
 The
 .Fn strsignal
 function accepts a signal number argument
 .Fa sig
 and returns a pointer to the corresponding message string.
 .Pp
 The
 .Fn psignal
 function accepts a signal number argument
 .Fa sig
 and writes it to the standard error.
 If the argument
 .Fa s
 is
 .Pf non- Dv NULL
 and does not point to the null character,
 .Fa s
 is written to the standard error file descriptor
 prior to the message string,
 immediately followed by a colon and a space.
 If the signal number is not recognized
 .Pq Xr sigaction 2 ,
 the string
 .Dq "Unknown signal"
 is produced.
 .Pp
 The
 .Fn psiginfo
 function is similar to
 .Fn psignal ,
 except that the signal number information is taken from the
 .Fa si
 argument which is a
 .Vt siginfo_t
 structure.
 .Pp
 The message strings can be accessed directly
 through the external array
 .Va sys_siglist ,
 indexed by recognized signal numbers.
 The external array
 .Va sys_signame
 is used similarly and
 contains short, upper-case abbreviations for signals
 which are useful for recognizing signal names
 in user input.
 The defined variable
 .Dv NSIG
 contains a count of the strings in
 .Va sys_siglist
 and
 .Va sys_signame .
 .Pp
 The
 .Fn sig2str
 function translates the signal number
 .Fa signum
 to the signal name, without the
 .Dq SIG
 prefix, and stores it at the location specified by
 .Fa str ,
 which should be large enough to hold the name and the terminating
 .Dv NUL
 byte.
 The symbol
 .Dv SIG2STR_MAX
 gives the maximum size in bytes required.
 .Pp
 The
 .Fn str2sig
 function translates the signal name
 .Fa str
 to a signal number and stores it in the location referenced by
 .Fa pnum .
 The name in
 .Fa str
 can be either the name of the signal, with or without the
 .Dq SIG
 prefix, or a decimal number.
+.Sh RETURN VALUES
+The
+.Fn sig2str
+and
+.Fn str2sig
+return 0 on success and -1 on translation failure.
+In the latter case the memory to store the translation result is left intact.
 .Sh SEE ALSO
 .Xr sigaction 2 ,
 .Xr perror 3 ,
 .Xr strerror 3
 .Sh STANDARDS
 The
 .Fn psignal
 and
 .Fn psiginfo
 functions are defined by
 .St -p1003.1-2008
 , while the
 .Fn sig2str
 and
 .Fn str2sig
 functions are defined by
 .St -p1003.1-2024 .
 .Sh HISTORY
 The
 .Fn psignal
 function appeared in
 .Bx 4.2 .
 The
 .Fn psiginfo
 function appeared in
 .Fx 14.3 ,
 .Nx 6.0 ,
 and
 .Dx 4.1 .
 The
 .Fn sig2str
 and
 .Fn str2sig
 functions appeared in
 .Fx 15.0 .