diff --git a/dhcp-4.1.0-add_timeout_when_NULL.patch b/dhcp-4.1.0-add_timeout_when_NULL.patch
new file mode 100644
index 0000000..e5da872
--- /dev/null
+++ b/dhcp-4.1.0-add_timeout_when_NULL.patch
@@ -0,0 +1,14 @@
+diff -up dhcp-4.1.0/common/dispatch.c.dracut dhcp-4.1.0/common/dispatch.c
+--- dhcp-4.1.0/common/dispatch.c.dracut	2008-01-23 16:43:04.000000000 -1000
++++ dhcp-4.1.0/common/dispatch.c	2009-06-25 16:21:03.000000000 -1000
+@@ -104,6 +104,10 @@ void add_timeout (when, where, what, ref
+ {
+ 	struct timeout *t, *q;
+ 
++	if (when == NULL) {
++		return;
++	}
++
+ 	/* See if this timeout supersedes an existing timeout. */
+ 	t = (struct timeout *)0;
+ 	for (q = timeouts; q; q = q -> next) {
diff --git a/dhcp.spec b/dhcp.spec
index 5b13eaf..61ac03a 100644
--- a/dhcp.spec
+++ b/dhcp.spec
@@ -186,7 +186,7 @@ libdhcpctl and libomapi static libraries are also included in this package.
 %patch17 -p1
 
 # If the ipv6 kernel module is missing, do not segfault
-# (Submitted to dhcp-bugs@isc.org - [ISC-Bugs #19367]
+# (Submitted to dhcp-bugs@isc.org - [ISC-Bugs #19367])
 %patch18 -p1
 
 # Read only up to IFNAMSIZ characters for the interface name in dhcpd (#441524)
@@ -194,6 +194,7 @@ libdhcpctl and libomapi static libraries are also included in this package.
 
 # Handle cases in add_timeout() where the function is called with a NULL
 # value for the 'when' parameter
+# (Submitted to dhcp-bugs@isc.org - [ISC-Bugs #19867])
 %patch20 -p1
 
 # Copy in documentation and example scripts for LDAP patch to dhcpd