diff --git a/lib/database_cleaner/moped/truncation_base.rb b/lib/database_cleaner/moped/truncation_base.rb
index e4d5bf3..f288789 100644
--- a/lib/database_cleaner/moped/truncation_base.rb
+++ b/lib/database_cleaner/moped/truncation_base.rb
@@ -23,7 +23,7 @@ module DatabaseCleaner
           session.use(db)
         end
 
-        session['system.namespaces'].find(:name => { '$not' => /system|\$/ }).to_a.map do |collection|
+        session['system.namespaces'].find(:name => { '$not' => /\.system\.|\$/ }).to_a.map do |collection|
           _, name = collection['name'].split('.', 2)
           name
         end