diff --git a/etc/default/zfs.in b/etc/default/zfs.in
index ae813e9de..5202cf502 100644
--- a/etc/default/zfs.in
+++ b/etc/default/zfs.in
@@ -60,6 +60,10 @@ ZPOOL_IMPORT_ALL_VISIBLE='no'
 # This is a space separated list.
 #ZFS_POOL_EXCEPTIONS="test2"
 
+# Additional important (operating system) file systems to mount beside
+# the root file system.
+#ZFS_INITRD_ADDITIONAL_DATASETS="rpool/usr rpool/var rpool/var/spool"
+
 # Should the datasets be mounted verbosely?
 # A mount counter will be used when mounting if set to 'yes'.
 VERBOSE_MOUNT='no'
diff --git a/etc/zfs/zfs-functions.in b/etc/zfs/zfs-functions.in
index 9ae8b40d4..5d646e9ea 100644
--- a/etc/zfs/zfs-functions.in
+++ b/etc/zfs/zfs-functions.in
@@ -109,7 +109,7 @@ fi
 # ----------------------------------------------------
 
 export ZFS ZED ZPOOL ZPOOL_CACHE ZFS_LOAD_KEY ZFS_UNLOAD_KEY ZFS_MOUNT ZFS_UNMOUNT \
-    ZFS_SHARE ZFS_UNSHARE
+    ZFS_SHARE ZFS_UNSHARE ZFS_POOL_EXCEPTIONS ZFS_INITRD_ADDITIONAL_DATASETS
 
 zfs_action()
 {