diff --git a/module/zfs/zfs_ioctl.c b/module/zfs/zfs_ioctl.c
index 534df5a06..109762795 100644
--- a/module/zfs/zfs_ioctl.c
+++ b/module/zfs/zfs_ioctl.c
@@ -2998,6 +2998,9 @@ zfs_fill_zplprops_impl(objset_t *os, uint64_t zplver,
 
 	ASSERT(zplprops != NULL);
 
+	if (os != NULL && os->os_phys->os_type != DMU_OST_ZFS)
+		return (SET_ERROR(EINVAL));
+
 	/*
 	 * Pull out creator prop choices, if any.
 	 */
diff --git a/module/zfs/zfs_vfsops.c b/module/zfs/zfs_vfsops.c
index 0b8214e0f..40fd5f764 100644
--- a/module/zfs/zfs_vfsops.c
+++ b/module/zfs/zfs_vfsops.c
@@ -2058,8 +2058,10 @@ zfs_get_zplprop(objset_t *os, zfs_prop_t prop, uint64_t *value)
 	else
 		pname = zfs_prop_to_name(prop);
 
-	if (os != NULL)
+	if (os != NULL) {
+		ASSERT3U(os->os_phys->os_type, ==, DMU_OST_ZFS);
 		error = zap_lookup(os, MASTER_NODE_OBJ, pname, 8, 1, value);
+	}
 
 	if (error == ENOENT) {
 		/* No value set, use the default value */