diff --git a/lib/searchkick/index.rb b/lib/searchkick/index.rb
index <HASH>..<HASH> 100644
--- a/lib/searchkick/index.rb
+++ b/lib/searchkick/index.rb
@@ -58,7 +58,11 @@ module Searchkick
     end
 
     def klass_document_type(klass)
-      klass.model_name.to_s.underscore
+      if klass.respond_to?(:document_type)
+        klass.document_type
+      else
+        klass.model_name.to_s.underscore
+      end
     end
 
     protected
Added ability to change document_type on a class level - closes #<I>