diff --git a/man/man4/zfs.4 b/man/man4/zfs.4
index 50c13b67bb..ac6474770a 100644
--- a/man/man4/zfs.4
+++ b/man/man4/zfs.4
@@ -15,7 +15,7 @@
 .\" own identifying information:
 .\" Portions Copyright [yyyy] [name of copyright owner]
 .\"
-.Dd December 21, 2022
+.Dd January 10, 2023
 .Dt ZFS 4
 .Os
 .
@@ -228,6 +228,12 @@ relative to the pool.
 Make some blocks above a certain size be gang blocks.
 This option is used by the test suite to facilitate testing.
 .
+.It Sy zfs_default_bs Ns = Ns Sy 9 Po 512 B Pc Pq int
+Default dnode block size as a power of 2.
+.
+.It Sy zfs_default_ibs Ns = Ns Sy 17 Po 128 KiB Pc Pq int
+Default dnode indirect block size as a power of 2.
+.
 .It Sy zfs_history_output_max Ns = Ns Sy 1048576 Ns B Ns B Po 1MB Pc Pq int
 When attempting to log an output nvlist of an ioctl in the on-disk history,
 the output will not be stored if it is larger than this size (in bytes).
diff --git a/module/zfs/dnode.c b/module/zfs/dnode.c
index 8e55d54479..b0d00adf42 100644
--- a/module/zfs/dnode.c
+++ b/module/zfs/dnode.c
@@ -2595,3 +2595,8 @@ EXPORT_SYMBOL(dnode_free_range);
 EXPORT_SYMBOL(dnode_evict_dbufs);
 EXPORT_SYMBOL(dnode_evict_bonus);
 #endif
+
+ZFS_MODULE_PARAM(zfs, zfs_, default_bs, INT, ZMOD_RW,
+	"Default dnode block shift");
+ZFS_MODULE_PARAM(zfs, zfs_, default_ibs, INT, ZMOD_RW,
+	"Default dnode indirect block shift");