diff --git a/docs/relations.rst b/docs/relations.rst
index 55b3f38..0dbf512 100644
--- a/docs/relations.rst
+++ b/docs/relations.rst
@@ -72,6 +72,8 @@ These relations can not be mapped to `simple` linestrings or polygons as they ca
 
 The Imposm table types ``relation`` and ``relation_member`` allow you to import all relevant data for these relations.
 
+.. note:: ``relation`` and ``relation_member`` require :ref:`load_all<tags>` to have access to all keys.
+
 ``relation_member``
 ^^^^^^^^^^^^^^^^^^^
 
diff --git a/mapping/filter.go b/mapping/filter.go
index 5e7e48a..d5507d6 100644
--- a/mapping/filter.go
+++ b/mapping/filter.go
@@ -132,6 +132,9 @@ func (f *RelationTagFilter) Filter(tags *element.Tags) bool {
 	if tags == nil {
 		return false
 	}
+
+	// TODO improve filtering for relation/relation_member mappings
+	// right now this only works with tags.load_all:true
 	if t, ok := (*tags)["type"]; ok {
 		if t != "multipolygon" && t != "boundary" && t != "land_area" {
 			*tags = nil