diff --git a/sys/compat/linprocfs/linprocfs.c b/sys/compat/linprocfs/linprocfs.c
index c95661d5294..b346fe84f7c 100644
--- a/sys/compat/linprocfs/linprocfs.c
+++ b/sys/compat/linprocfs/linprocfs.c
@@ -1452,6 +1452,19 @@ linprocfs_domsgmnb(PFS_FILL_ARGS)
 	return (0);
 }
 
+/*
+ * Filler function for proc/sys/kernel/ngroups_max
+ *
+ * Note that in Linux it defaults to 65536, not 1023.
+ */
+static int
+linprocfs_dongroups_max(PFS_FILL_ARGS)
+{
+
+	sbuf_printf(sb, "%d\n", ngroups_max);
+	return (0);
+}
+
 /*
  * Filler function for proc/sys/kernel/pid_max
  */
@@ -1922,6 +1935,8 @@ linprocfs_init(PFS_INIT_ARGS)
 	    NULL, NULL, NULL, PFS_RD);
 	pfs_create_file(dir, "msgmnb", &linprocfs_domsgmnb,
 	    NULL, NULL, NULL, PFS_RD);
+	pfs_create_file(dir, "ngroups_max", &linprocfs_dongroups_max,
+	    NULL, NULL, NULL, PFS_RD);
 	pfs_create_file(dir, "pid_max", &linprocfs_dopid_max,
 	    NULL, NULL, NULL, PFS_RD);
 	pfs_create_file(dir, "sem", &linprocfs_dosem,