diff --git a/app/models/artefact.rb b/app/models/artefact.rb
index <HASH>..<HASH> 100644
--- a/app/models/artefact.rb
+++ b/app/models/artefact.rb
@@ -25,6 +25,9 @@ class Artefact
   field "tag_ids",              type: Array, default: []
   field "primary_section",      type: String
 
+  index "tag_ids"
+  index "primary_section"
+
   MAXIMUM_RELATED_ITEMS = 8
 
   FORMATS = [
diff --git a/app/models/tag.rb b/app/models/tag.rb
index <HASH>..<HASH> 100644
--- a/app/models/tag.rb
+++ b/app/models/tag.rb
@@ -5,6 +5,7 @@ class Tag
   field :tag_type, type: String #TODO: list of accepted types?
 
   index :tag_id, unique: true
+  index :tag_type
 
   validates_presence_of :tag_id, :title, :tag_type
Add tag and section indices to artefacts and tags.