diff --git a/Cantera/src/thermo/SpeciesThermoMgr.h b/Cantera/src/thermo/SpeciesThermoMgr.h
index 8b4bf1ff0..af982c7c9 100755
--- a/Cantera/src/thermo/SpeciesThermoMgr.h
+++ b/Cantera/src/thermo/SpeciesThermoMgr.h
@@ -499,7 +499,7 @@ namespace Cantera {
     
     m_thermo1 = right.m_thermo1;
     m_thermo2 = right.m_thermo2;
-    m_p0 = m_p0;
+    m_p0      = right.m_p0;
     speciesToType = right.speciesToType;
     
     return *this;