diff --git a/Cantera/src/Phase.cpp b/Cantera/src/Phase.cpp
index 119da5521..56434a495 100755
--- a/Cantera/src/Phase.cpp
+++ b/Cantera/src/Phase.cpp
@@ -26,11 +26,11 @@ namespace Cantera {
             getMassFractions(state + 2);
         }
 
-        void Phase::restoreState(vector_fp& state) {
+        void Phase::restoreState(const vector_fp& state) {
             restoreState(state.size(),state.begin());
         }
 
-        void Phase::restoreState(int lenstate, doublereal* state) {
+        void Phase::restoreState(int lenstate, const doublereal* state) {
             if (int(lenstate) >= nSpecies() + 2) {
                 setMassFractions_NoNorm(state + 2);
                 setTemperature(state[0]);
diff --git a/Cantera/src/Phase.h b/Cantera/src/Phase.h
index d32191cfb..7c78d7f75 100755
--- a/Cantera/src/Phase.h
+++ b/Cantera/src/Phase.h
@@ -73,9 +73,9 @@ namespace Cantera {
         /**
          * Restore a state saved on a previous call to saveState.
          */
-        void restoreState(vector_fp& state);
+        void restoreState(const vector_fp& state);
 
-        void restoreState(int lenstate, doublereal* state);
+        void restoreState(int lenstate, const doublereal* state);
 
         /**
          * Set the species mole fractions by name. 
@@ -185,8 +185,9 @@ namespace Cantera {
 	 */
 	int m_kk;
 	/**
-	 * m_ndim is the dimensionality of the phase. Basically, volumetric phases
-	 * have dimensionality 3 and surface phases have dimensionality 2.
+	 * m_ndim is the dimensionality of the phase. 
+	 * Volumetric phases have dimensionality 3 and surface phases
+	 * have dimensionality 2.
 	 */
         int m_ndim;
 	/**