1 files changed, 10 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/scoping/named.rb b/activerecord/lib/active_record/scoping/named.rb
index 2a5718f388..35420e6551 100644
--- a/activerecord/lib/active_record/scoping/named.rb
+++ b/activerecord/lib/active_record/scoping/named.rb
@@ -139,6 +139,16 @@ module ActiveRecord
         #   Article.published.featured.latest_article
         #   Article.featured.titles
         def scope(name, body, &block)
+          unless body.respond_to?(:call)
+            raise ArgumentError, 'The scope body needs to be callable.'
+          end
+
+          if dangerous_class_method?(name)
+            raise ArgumentError, "You tried to define a scope named \"#{name}\" " \
+              "on the model \"#{self.name}\", but Active Record already defined " \
+              "a class method with the same name."
+          end
+
           extension = Module.new(&block) if block
 
           singleton_class.send(:define_method, name) do |*args|