diff --git a/Cantera/src/thermo/mix_defs.h b/Cantera/src/thermo/mix_defs.h
index 32e72bf12..fef148800 100755
--- a/Cantera/src/thermo/mix_defs.h
+++ b/Cantera/src/thermo/mix_defs.h
@@ -110,6 +110,7 @@ namespace Cantera {
   const int cLineKinetics = 5;
   const int cEdgeKinetics = 6;
   const int cSolidKinetics = 7;
+  const int cAqueousKinetics = 8;
 }
 
 #endif