diff --git a/src/conversion/ensight/file/ensightFile.C b/src/conversion/ensight/file/ensightFile.C
index bcbdb6799a..46809d4ebe 100644
--- a/src/conversion/ensight/file/ensightFile.C
+++ b/src/conversion/ensight/file/ensightFile.C
@@ -278,7 +278,7 @@ Foam::Ostream& Foam::ensightFile::writeUndef()
 }
 
 
-Foam::Ostream& Foam::ensightFile::writeKeyword(const string& key)
+Foam::Ostream& Foam::ensightFile::writeKeyword(const keyType& key)
 {
     if (allowUndef_)
     {
diff --git a/src/conversion/ensight/file/ensightFile.H b/src/conversion/ensight/file/ensightFile.H
index ea4a29da00..faf07bd265 100644
--- a/src/conversion/ensight/file/ensightFile.H
+++ b/src/conversion/ensight/file/ensightFile.H
@@ -147,7 +147,7 @@ public:
         virtual Ostream& write(const char* buf, std::streamsize count);
 
         //- Write element keyword with trailing newline, optionally with undef
-        virtual Ostream& writeKeyword(const string& key);
+        virtual Ostream& writeKeyword(const keyType&);
 
         //- Write "C Binary" for binary files (eg, geometry/measured)
         Ostream& writeBinaryHeader();
diff --git a/src/conversion/ensight/file/ensightGeoFile.C b/src/conversion/ensight/file/ensightGeoFile.C
index 749a5d1542..214a882a5e 100644
--- a/src/conversion/ensight/file/ensightGeoFile.C
+++ b/src/conversion/ensight/file/ensightGeoFile.C
@@ -72,7 +72,7 @@ Foam::ensightGeoFile::~ensightGeoFile()
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
-Foam::Ostream& Foam::ensightGeoFile::writeKeyword(const string& key)
+Foam::Ostream& Foam::ensightGeoFile::writeKeyword(const keyType& key)
 {
     write(key); newline();
 
diff --git a/src/conversion/ensight/file/ensightGeoFile.H b/src/conversion/ensight/file/ensightGeoFile.H
index 0fb9896bf0..75cef26cd9 100644
--- a/src/conversion/ensight/file/ensightGeoFile.H
+++ b/src/conversion/ensight/file/ensightGeoFile.H
@@ -88,7 +88,7 @@ public:
     // Output
 
         //- Write keyword with trailing newline
-        virtual Ostream& writeKeyword(const string& key);
+        virtual Ostream& writeKeyword(const keyType& key);
 };
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //