diff --git a/trick_source/sim_services/CheckPointAgent/PythonPrint.cpp b/trick_source/sim_services/CheckPointAgent/PythonPrint.cpp
index a78393e0..ed529875 100644
--- a/trick_source/sim_services/CheckPointAgent/PythonPrint.cpp
+++ b/trick_source/sim_services/CheckPointAgent/PythonPrint.cpp
@@ -121,6 +121,7 @@ void Trick::PythonPrint::write_singleton( std::ostream& chkpnt_os, void* address
                 } else {
                     std::cerr << __FUNCTION__ << " enumeration size error." << std::endl;
                     std::cerr.flush();
+                    value = -1;
                 }
 
                 enum_attr = (ENUM_ATTR*)attr->attr;