kmx.io/rbpkg

diff --git a/lib/rbpkg/repo.rb b/lib/rbpkg/repo.rb
index fbe196c..61d895d 100644
--- a/lib/rbpkg/repo.rb
+++ b/lib/rbpkg/repo.rb
@@ -331,9 +331,9 @@ class Rbpkg::Repo
     cmd! "cd #{sh_quote(src_dir!)} && git pull && git submodule update"
   end
 
-  @@required_by = nil
+  @required_by = nil
   def required_by
-    @@required_by || @@required_by =
+    @required_by || @required_by =
       begin
         r = []
         Rbpkg::Repos.repos.each do |repo_name, repo_class|