1 files changed, 15 insertions, 9 deletions
diff --git a/mrblib/class.rb b/mrblib/class.rb
index 4f268b6c8..6d624ee83 100644
--- a/mrblib/class.rb
+++ b/mrblib/class.rb
@@ -1,18 +1,24 @@
 class Module
   # 15.2.2.4.13
   def attr_reader(*names)
-    names.each{|name|
-      name2 = ('@'+name.to_s).intern
-      define_method(name){self.instance_variable_get(name2)}
-    }
+    names.each do |name|
+      name = name.to_s
+      raise(NameError, "#{name.inspect} is not allowed as an instance variable name") if name.include?('@') || name.include?('?')  || name.include?('$')
+      
+      attr_name = '@'+name
+      define_method(name){self.instance_variable_get(attr_name)}
+    end
   end
   # 15.2.2.4.14
   def attr_writer(*names)
-    names.each{|name|
-      name2 = ('@'+name.to_s).intern
-      name = (name.to_s+"=").intern
-      define_method(name){|v|self.instance_variable_set(name2,v)}
-    }
+    names.each do |name|
+      name = name.to_s
+      raise(NameError, "#{name.inspect} is not allowed as an instance variable name") if name.include?('@') || name.include?('?')  || name.include?('$')
+      
+      attr_name = '@'+name
+      name = (name+"=").intern
+      define_method(name){|v|self.instance_variable_set(attr_name,v)}
+    end
   end
   # 15.2.2.4.12
   def attr_accessor(*names)