diff --git a/share/man/man5/src.conf.5 b/share/man/man5/src.conf.5
--- a/share/man/man5/src.conf.5
+++ b/share/man/man5/src.conf.5
@@ -1,5 +1,5 @@
 .\" DO NOT EDIT-- this file is @generated by tools/build/options/makeman.
-.Dd May 5, 2025
+.Dd May 9, 2025
 .Dt SRC.CONF 5
 .Os
 .Sh NAME
@@ -1896,6 +1896,11 @@
 .El
 .It Va WITH_ZONEINFO_LEAPSECONDS_SUPPORT
 Build leapsecond information in to the timezone database.
+This option violates
+.St -p1003.1
+and all other applicable standards, and is known to cause unexpected
+issues with date/time handling in many applications and programming
+languages.
 .El
 .Pp
 The following options accept a single value from a list of valid values.
diff --git a/tools/build/options/WITH_ZONEINFO_LEAPSECONDS_SUPPORT b/tools/build/options/WITH_ZONEINFO_LEAPSECONDS_SUPPORT
--- a/tools/build/options/WITH_ZONEINFO_LEAPSECONDS_SUPPORT
+++ b/tools/build/options/WITH_ZONEINFO_LEAPSECONDS_SUPPORT
@@ -1 +1,6 @@
 Build leapsecond information in to the timezone database.
+This option violates
+.St -p1003.1
+and all other applicable standards, and is known to cause unexpected
+issues with date/time handling in many applications and programming
+languages.