diff --git a/gtsam/linear/PCGSolver.h b/gtsam/linear/PCGSolver.h
index 3e72c7cbe..7752902ba 100644
--- a/gtsam/linear/PCGSolver.h
+++ b/gtsam/linear/PCGSolver.h
@@ -48,6 +48,7 @@ public:
     return *preconditioner_;
   }
 
+  // needed for python wrapper
   void print(const std::string &s) const;
 
   boost::shared_ptr<PreconditionerParameters> preconditioner_;