diff --git a/Cantera/src/CVode.h b/Cantera/src/CVode.h
index 335f08375..8e7e62723 100755
--- a/Cantera/src/CVode.h
+++ b/Cantera/src/CVode.h
@@ -30,7 +30,7 @@ namespace Cantera {
      */
     class CVodeErr : public CanteraError {
     public:
-        CVodeErr(string msg) : CanteraError("CVodeInt", msg){}
+        CVodeErr(std::string msg) : CanteraError("CVodeInt", msg){}
     };
 
 
diff --git a/Cantera/src/ODE_integrators.cpp b/Cantera/src/ODE_integrators.cpp
index fbf53d89f..177d6d4c2 100644
--- a/Cantera/src/ODE_integrators.cpp
+++ b/Cantera/src/ODE_integrators.cpp
@@ -9,7 +9,7 @@
 
 namespace Cantera {
 
-    Integrator* newIntegrator(string itype) {
+    Integrator* newIntegrator(std::string itype) {
         if (itype == "CVODE") {
 #ifdef HAS_SUNDIALS
             return new CVodesIntegrator();