diff --git a/src/common/filterparameter.cpp b/src/common/filterparameter.cpp
index e257967b7..69e3df3bf 100644
--- a/src/common/filterparameter.cpp
+++ b/src/common/filterparameter.cpp
@@ -849,7 +849,7 @@ RichString::~RichString()
 RichMatrix44f::RichMatrix44f( const QString nm,const vcg::Matrix44f& defval,const QString desc/*=QString()*/,const QString tltip/*=QString()*/ ) :RichParameter(nm,new Matrix44fValue(defval),new Matrix44fDecoration(new Matrix44fValue(defval),desc,tltip)) { }
 RichMatrix44f::RichMatrix44f( const QString nm,const vcg::Matrix44d& defval,const QString desc/*=QString()*/,const QString tltip/*=QString()*/ ) :RichParameter(nm,new Matrix44fValue(defval),new Matrix44fDecoration(new Matrix44fValue(defval),desc,tltip)) { }
 
-RichMatrix44f::RichMatrix44f(const QString nm, const vcg::Matrix44f& val, const vcg::Matrix44f& defval, const QString desc /*= QString()*/, const QString tltip /*= QString()*/, bool isxmlpar /*= false*/)
+RichMatrix44f::RichMatrix44f(const QString nm, const vcg::Matrix44f& val, const vcg::Matrix44f& defval, const QString desc /*= QString()*/, const QString tltip /*= QString()*/, bool /*isxmlpar = false*/)
 	: RichParameter(nm, new Matrix44fValue(val), new Matrix44fDecoration(new Matrix44fValue(defval), desc, tltip)) { }
 
 void RichMatrix44f::accept( Visitor& v )