diff --git a/activerecord/lib/active_record/relation/predicate_builder/array_handler.rb b/activerecord/lib/active_record/relation/predicate_builder/array_handler.rb
index fb08326..d4e74eb 100644
--- a/activerecord/lib/active_record/relation/predicate_builder/array_handler.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder/array_handler.rb
@@ -14,7 +14,8 @@ def call(attribute, value)
             it for 'IN' conditions.
           MSG
 
-          values = values.flatten
+          flat_values = values.flatten
+          values = flat_values unless flat_values.include?(nil)
         end
 
         return attribute.in([]) if values.empty? && nils.empty?