diff --git a/liberty/Liberty.cc b/liberty/Liberty.cc
index 449fc551..be42b1bc 100644
--- a/liberty/Liberty.cc
+++ b/liberty/Liberty.cc
@@ -136,6 +136,9 @@ LibertyLibrary::~LibertyLibrary()
   delete inverters_;
   driver_waveform_map_.deleteContents();
   delete driver_waveform_default_;
+
+  delete default_ocv_derate_;
+  default_ocv_derate_ = nullptr;
 }
 
 LibertyCell *