diff --git a/lib/searchkick/relation.rb b/lib/searchkick/relation.rb
index 1618253..7d2ae36 100644
--- a/lib/searchkick/relation.rb
+++ b/lib/searchkick/relation.rb
@@ -172,6 +172,16 @@ module Searchkick
       self
     end
 
+    # TODO support boost_by(:order, :other)
+    def boost_by(value)
+      spawn.boost_by!(value)
+    end
+
+    def boost_by!(value)
+      options[:boost_by] = value
+      self
+    end
+
     # same as Active Record
     def inspect
       entries = results.first(11).map!(&:inspect)
diff --git a/test/boost_test.rb b/test/boost_test.rb
index 7aa5eab..01a6eb8 100644
--- a/test/boost_test.rb
+++ b/test/boost_test.rb
@@ -115,6 +115,7 @@ class BoostTest < Minitest::Test
     ]
     assert_order "tomato", ["Tomato C", "Tomato B", "Tomato A"], boost_by: [:orders_count]
     assert_order "tomato", ["Tomato C", "Tomato B", "Tomato A"], boost_by: {orders_count: {factor: 10}}
+    assert_order_relation ["Tomato C", "Tomato B", "Tomato A"], Product.search("tomato", relation: true).boost_by(orders_count: {factor: 10})
   end
 
   def test_boost_by_missing
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 2fd23fa..cb06959 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -95,6 +95,10 @@ class Minitest::Test
     assert_equal expected, klass.search(term, **options).map(&:name)
   end
 
+  def assert_order_relation(expected, relation)
+    assert_equal expected, relation.map(&:name)
+  end
+
   def assert_equal_scores(term, options = {}, klass = Product)
     assert_equal 1, klass.search(term, **options).hits.map { |a| a["_score"] }.uniq.size
   end
--
libgit2 0.21.0