diff --git a/lib/ransack/adapters/active_record/ransack/nodes/condition.rb b/lib/ransack/adapters/active_record/ransack/nodes/condition.rb
index fb0210dbf..df5c2ac3e 100644
--- a/lib/ransack/adapters/active_record/ransack/nodes/condition.rb
+++ b/lib/ransack/adapters/active_record/ransack/nodes/condition.rb
@@ -18,6 +18,7 @@ def arel_predicate
             predicates.inject(&:or)
           end
         else
+          predicates.first.right[0] = predicates.first.right[0].val if defined?(Arel::Nodes::Casted) && predicates.first.class == Arel::Nodes::In && predicates.first.right.is_a?(Array) && predicates.first.right[0].class == Arel::Nodes::Casted
           predicates.first
         end
       end
diff --git a/spec/ransack/adapters/active_record/base_spec.rb b/spec/ransack/adapters/active_record/base_spec.rb
index dd3c3aad3..20d01943a 100644
--- a/spec/ransack/adapters/active_record/base_spec.rb
+++ b/spec/ransack/adapters/active_record/base_spec.rb
@@ -161,6 +161,11 @@ def self.sane_adapter?
             expect(s.result.to_a).to eq [p]
           end
 
+          it "should function correctly when an array is passed into custom ransacker with _in" do
+            s = Person.search(array_users_in: true)
+            expect(s.result.length).to be > 0
+          end
+
           it "should function correctly when an attribute name ends with '_start'" do
             p = Person.create!(:new_start => 'Bar and foo', :name => 'Xiang')
 
diff --git a/spec/support/schema.rb b/spec/support/schema.rb
index 52073ed84..33f312677 100644
--- a/spec/support/schema.rb
+++ b/spec/support/schema.rb
@@ -45,6 +45,10 @@ class Person < ActiveRecord::Base
     parent.table[:name]
   end
 
+  ransacker :array_users, formatter: proc { |v| Person.first(2).map(&:id) } do |parent|
+    parent.table[:id]
+  end
+
   ransacker :doubled_name do |parent|
     Arel::Nodes::InfixOperation.new(
       '||', parent.table[:name], parent.table[:name]