diff --git a/lib/libutil/kinfo_getfile.c b/lib/libutil/kinfo_getfile.c
index f1441bdf771..345da657df8 100644
--- a/lib/libutil/kinfo_getfile.c
+++ b/lib/libutil/kinfo_getfile.c
@@ -27,6 +27,10 @@ kinfo_getfile(pid_t pid, int *cntp)
 	error = sysctl(mib, nitems(mib), NULL, &len, NULL, 0);
 	if (error)
 		return (NULL);
+	/*
+	 * Add extra space as the table may grow between requesting the size
+	 * and fetching the data.
+	 */
 	len = len * 4 / 3;
 	buf = malloc(len);
 	if (buf == NULL)