diff --git a/NEWS b/NEWS
index ee21f717..406f103a 100644
--- a/NEWS
+++ b/NEWS
@@ -15,6 +15,7 @@ procps-ng-NEXT
   * sysctl: Add support for systemd glob patterns          issue #191
   * sysctl: Check resolved path to be under /proc/sys      issue #179
   * sysctl: return non-zero if EINVAL return for write     merge #76
+  * sysctl.conf.5: Note max line length                    issue #77
   * top: added LOGID similar to 3.3.13 ps LUID
   * top: added EXE identical to 3.3.17 ps EXE
   * top: exploit some library smaps_rollup provisions      issue #112
diff --git a/sysctl.conf.5 b/sysctl.conf.5
index f16597c5..535aad9d 100644
--- a/sysctl.conf.5
+++ b/sysctl.conf.5
@@ -6,7 +6,7 @@
 .\" but WITHOUT ANY WARRANTY; without even the implied warranty of
 .\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 .\" GNU General Public License for more details."
-.TH SYSCTL.CONF "5" "2020-06-04" "procps-ng" "File Formats"
+.TH SYSCTL.CONF "5" "2021-09-15" "procps-ng" "File Formats"
 .SH NAME
 sysctl.conf \- sysctl preload/configuration file
 .SH DESCRIPTION
@@ -41,6 +41,9 @@ Use
 or follow
 .BR sysctl (8)
 to list all possible parameters. The description of individual parameters can be found in the kernel documentation.
+
+Maximum supported line length of the value is 4096 characters due
+to a limitation of \fI/proc\fR entries in Linux kernel.
 .SH EXAMPLE
 .RS
 .sp