diff --git a/net-print/cnijfilter2/cnijfilter2-6.60.ebuild b/net-print/cnijfilter2/cnijfilter2-6.60.ebuild
index 0852a735215d8..81ab159fc828f 100644
--- a/net-print/cnijfilter2/cnijfilter2-6.60.ebuild
+++ b/net-print/cnijfilter2/cnijfilter2-6.60.ebuild
@@ -26,6 +26,7 @@ PATCHES=(
 	"${FILESDIR}"/${PN}-6.50-gentoo.patch
 	"${FILESDIR}"/${PN}-5.80-cflags.patch
 	"${FILESDIR}"/${PN}-5.80-fno-common.patch
+	"${FILESDIR}"/${P}-c99.patch
 )
 
 pkg_setup()  {
diff --git a/net-print/cnijfilter2/files/cnijfilter2-6.60-c99.patch b/net-print/cnijfilter2/files/cnijfilter2-6.60-c99.patch
new file mode 100644
index 0000000000000..d328d1d1f63c3
--- /dev/null
+++ b/net-print/cnijfilter2/files/cnijfilter2-6.60-c99.patch
@@ -0,0 +1,10 @@
+--- a/lgmon3/src/keytext.c	2024-02-20 07:45:11.719827112 +0100
++++ b/lgmon3/src/keytext.c	2024-02-20 07:46:15.504048256 +0100
+@@ -37,6 +37,7 @@
+ #include <unistd.h>
+ #include <libxml/parser.h>	/* Ver.2.80 */
+ #include <string.h>
++#include <stdlib.h>
+ 
+ #include "keytext.h"
+