diff --git a/lib/searchkick/index_options.rb b/lib/searchkick/index_options.rb
index ba57aec..1d5ddcb 100644
--- a/lib/searchkick/index_options.rb
+++ b/lib/searchkick/index_options.rb
@@ -7,11 +7,6 @@ module Searchkick
     end
 
     def index_options
-      if below70
-        index_type = options[:_type]
-        index_type = index_type.call if index_type.respond_to?(:call)
-      end
-
       custom_mapping = options[:mappings] || {}
       if below70 && custom_mapping.keys.map(&:to_sym).include?(:properties)
         # add type
@@ -504,6 +499,14 @@ module Searchkick
       end
     end
 
+    def index_type
+      @index_type ||= begin
+        index_type = options[:_type]
+        index_type = index_type.call if index_type.respond_to?(:call)
+        index_type
+      end
+    end
+
     def default_type
       "text"
     end
--
libgit2 0.21.0