diff --git a/EGkVector3d.h b/EGkVector3d.h
index 9d14ca2..d7fd357 100644
--- a/EGkVector3d.h
+++ b/EGkVector3d.h
@@ -72,7 +72,7 @@ class EGK_EXPORT Vector3d
       const Vector3d& operator /=( double dDiv)
              { double dMul = 1 / dDiv ; this->x *= dMul ; this->y *= dMul ; this->z *= dMul ; return *this ; }
       void ToSpherical( double* pdLen, double* pdAngVertDeg, double* pdAngOrizzDeg) const ;
-      bool Normalize( void) ;
+      bool Normalize( double dEps = EPS_SMALL) ;
       bool Rotate( const Vector3d& vtAx, double dAngRad) ;
       bool Rotate( const Vector3d& vtAx, double dCosAng, double dSinAng) ;
       bool Scale( const Frame3d& frRef, double dCoeffX, double dCoeffY, double dCoeffZ) ;