1 files changed, 4 insertions, 1 deletions
diff --git a/src/bp_sim.cpp b/src/bp_sim.cpp
index a1851b55..88e2c3ad 100755
--- a/src/bp_sim.cpp
+++ b/src/bp_sim.cpp
@@ -4137,7 +4137,10 @@ void CFlowGenListPerThread::start_generate_stateful(std::string erf_file_name,
 void CFlowGenList::Delete(){
     clean_p_thread_info();
     Clean();
-    delete  CPluginCallback::callback;
+    if (CPluginCallback::callback) {
+        delete  CPluginCallback::callback;
+        CPluginCallback::callback = NULL;
+    }
 }