diff --git a/lib/rubygems-requirements-system/system-repository.rb b/lib/rubygems-requirements-system/system-repository.rb
index d786f92..a435109 100644
--- a/lib/rubygems-requirements-system/system-repository.rb
+++ b/lib/rubygems-requirements-system/system-repository.rb
@@ -16,7 +16,8 @@
 module RubyGemsRequirementsSystem
   class SystemRepository
     attr_reader :id
-    protected attr_reader :properties
+    attr_reader :properties
+    protected :properties
     def initialize(id, properties)
       @id = id
       @properties = properties