1 files changed, 5 insertions, 4 deletions
diff --git a/activerecord/lib/active_record/inheritance.rb b/activerecord/lib/active_record/inheritance.rb
index f54865c86e..40976bc29e 100644
--- a/activerecord/lib/active_record/inheritance.rb
+++ b/activerecord/lib/active_record/inheritance.rb
@@ -116,9 +116,10 @@ module ActiveRecord
             begin
               constant = ActiveSupport::Dependencies.constantize(candidate)
               return constant if candidate == constant.to_s
-            rescue NameError => e
-              # We don't want to swallow NoMethodError < NameError errors
-              raise e unless e.instance_of?(NameError)
+            # We don't want to swallow NoMethodError < NameError errors
+            rescue NoMethodError
+              raise
+            rescue NameError
             end
           end
 
@@ -174,7 +175,7 @@ module ActiveRecord
         if subclass_name.present? && subclass_name != self.name
           subclass = subclass_name.safe_constantize
 
-          unless subclasses.include?(subclass)
+          unless descendants.include?(subclass)
             raise ActiveRecord::SubclassNotFound.new("Invalid single-table inheritance type: #{subclass_name} is not a subclass of #{name}")
           end