diff --git a/Modules/Applications/AppClassification/app/otbKMeansClassification.cxx b/Modules/Applications/AppClassification/app/otbKMeansClassification.cxx
index 8712de96d7e8485c3d41de5c8d7700e426960b07..fdaf181af8c18ab7572575760da1818ae04626ad 100644
--- a/Modules/Applications/AppClassification/app/otbKMeansClassification.cxx
+++ b/Modules/Applications/AppClassification/app/otbKMeansClassification.cxx
@@ -102,7 +102,7 @@ private:
 
     KMeansFileNamesHandler fileNames;
 
-    std::string fieldName = "field";
+    const std::string fieldName = "field";
 
     fileNames.CreateTemporaryFileNames(GetParameterString( "out" ));