diff --git a/include/AbstractState.h b/include/AbstractState.h
index 30c9bfb6..3ace7be4 100644
--- a/include/AbstractState.h
+++ b/include/AbstractState.h
@@ -395,6 +395,7 @@ public:
     ~AbstractStateWrapper(){delete this->p;};
     void update(long input_pair, double Value1, double Value2){ this->p->update(input_pair,Value1,Value2); };
     double keyed_output(int key) { return this->p->keyed_output(key); }
+    bool empty(){return (this->p == NULL);}
 };
 
 } /* namespace CoolProp */
diff --git a/src/HumidAirProp.cpp b/src/HumidAirProp.cpp
index 23be61f2..f233ffa3 100644
--- a/src/HumidAirProp.cpp
+++ b/src/HumidAirProp.cpp
@@ -16,8 +16,8 @@
 #include <string.h>
 #include <iostream>
 
-CoolProp::AbstractStateWrapper Water("HEOS", "Water");
-CoolProp::AbstractStateWrapper Air("HEOS", "Air");
+CoolProp::AbstractStateWrapper Water;
+CoolProp::AbstractStateWrapper Air;
 
 namespace HumidAir
 {
@@ -1075,6 +1075,14 @@ double HAPropsSI(const char *OutputName, const char *Input1Name, double Input1,
 {
     try
     {
+        
+        if (Water.empty()){
+            Water = CoolProp::AbstractStateWrapper("HEOS", "Water");
+        }
+        if (Air.empty()){
+            Air = CoolProp::AbstractStateWrapper("HEOS", "Air");
+        }
+        
         int In1Type, In2Type, In3Type,iT,iW,iTdp,iRH,ip,Type1,Type2;
         double vals[3],p,T,RH,W,Tdp,psi_w,M_ha,v_bar,h_bar,s_bar,MainInputValue,SecondaryInputValue,T_guess;
         double Value1,Value2,W_guess;