diff --git a/src/lib/libc/stdlib/abs.3 b/src/lib/libc/stdlib/abs.3
index 420bdf6f..afacc985 100644
--- a/src/lib/libc/stdlib/abs.3
+++ b/src/lib/libc/stdlib/abs.3
@@ -29,15 +29,16 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"	$OpenBSD: abs.3,v 1.11 2013/07/17 05:42:11 schwarze Exp $
+.\"	$OpenBSD: abs.3,v 1.12 2019/01/18 07:32:17 schwarze Exp $
 .\"
-.Dd $Mdocdate: July 17 2013 $
+.Dd $Mdocdate: January 18 2019 $
 .Dt ABS 3
 .Os
 .Sh NAME
 .Nm abs
 .Nd integer absolute value function
 .Sh SYNOPSIS
+.In limits.h
 .In stdlib.h
 .Ft int
 .Fn abs "int j"
@@ -66,5 +67,9 @@ The
 .Fn abs
 function first appeared in
 .At v6 .
-.Sh BUGS
-The absolute value of the most negative integer remains negative.
+.Sh CAVEATS
+The result of applying
+.Fn abs
+to
+.Dv INT_MIN
+is undefined.
diff --git a/src/lib/libc/stdlib/imaxabs.3 b/src/lib/libc/stdlib/imaxabs.3
index 6e280dda..340be61b 100644
--- a/src/lib/libc/stdlib/imaxabs.3
+++ b/src/lib/libc/stdlib/imaxabs.3
@@ -29,9 +29,9 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"	$OpenBSD: imaxabs.3,v 1.7 2014/11/30 21:21:59 schwarze Exp $
+.\"	$OpenBSD: imaxabs.3,v 1.8 2019/01/18 07:32:17 schwarze Exp $
 .\"
-.Dd $Mdocdate: November 30 2014 $
+.Dd $Mdocdate: January 18 2019 $
 .Dt IMAXABS 3
 .Os
 .Sh NAME
@@ -39,6 +39,7 @@
 .Nd integer absolute value function
 .Sh SYNOPSIS
 .In inttypes.h
+.In stdint.h
 .Ft intmax_t
 .Fn imaxabs "intmax_t j"
 .Sh DESCRIPTION
@@ -61,5 +62,9 @@ The
 .Fn imaxabs
 function conforms to
 .St -isoC-99 .
-.Sh BUGS
-The absolute value of the most negative integer remains negative.
+.Sh CAVEATS
+The result of applying
+.Fn imaxabs
+to
+.Dv INTMAX_MIN
+is undefined.
diff --git a/src/lib/libc/stdlib/labs.3 b/src/lib/libc/stdlib/labs.3
index 37a20b42..f3fd6fd5 100644
--- a/src/lib/libc/stdlib/labs.3
+++ b/src/lib/libc/stdlib/labs.3
@@ -29,9 +29,9 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"	$OpenBSD: labs.3,v 1.16 2017/08/01 14:57:02 schwarze Exp $
+.\"	$OpenBSD: labs.3,v 1.17 2019/01/18 07:32:17 schwarze Exp $
 .\"
-.Dd $Mdocdate: August 1 2017 $
+.Dd $Mdocdate: January 18 2019 $
 .Dt LABS 3
 .Os
 .Sh NAME
@@ -40,6 +40,7 @@
 .Nm qabs
 .Nd return the absolute value of a long integer
 .Sh SYNOPSIS
+.In limits.h
 .In stdlib.h
 .Ft long
 .Fn labs "long i"
@@ -73,5 +74,15 @@ and
 .Fn llabs
 functions conform to
 .St -isoC-99 .
-.Sh BUGS
-The absolute value of the most negative integer remains negative.
+.Sh CAVEATS
+The results of applying
+.Fn labs
+to
+.Dv LONG_MIN
+and
+.Fn llabs
+to
+.Dv LLONG_MIN
+are undefined, and
+.Fn qabs
+is not portable in the first place.