diff --git a/src/lagrangian/intermediate/phaseProperties/phaseProperties/phaseProperties.C b/src/lagrangian/intermediate/phaseProperties/phaseProperties/phaseProperties.C
index 9ad0a61a2e002b00179e22b7782d00f54da1e973..1da916150845d91850dd915f704cdaf20edaed87 100644
--- a/src/lagrangian/intermediate/phaseProperties/phaseProperties/phaseProperties.C
+++ b/src/lagrangian/intermediate/phaseProperties/phaseProperties/phaseProperties.C
@@ -171,7 +171,7 @@ void Foam::phaseProperties::checkTotalMassFraction() const
 }
 
 
-Foam::word Foam::phaseProperties::phaseToStateLabel(phaseType pt) const
+Foam::word Foam::phaseProperties::phaseToStateLabel(const phaseType pt) const
 {
     word state = "(unknown)";
     switch (pt)
diff --git a/src/lagrangian/intermediate/phaseProperties/phaseProperties/phaseProperties.H b/src/lagrangian/intermediate/phaseProperties/phaseProperties/phaseProperties.H
index 7e8b3051432a3401563f40478531745ebcdad065..730d99fbb5b744f82ce9ec49fbf8208406ee7bdc 100644
--- a/src/lagrangian/intermediate/phaseProperties/phaseProperties/phaseProperties.H
+++ b/src/lagrangian/intermediate/phaseProperties/phaseProperties/phaseProperties.H
@@ -107,7 +107,7 @@ private:
         void checkTotalMassFraction() const;
 
         //- Set the state label
-        word phaseToStateLabel(phaseType pt) const;
+        word phaseToStateLabel(const phaseType pt) const;
 
 
 public: