We respond to the paper by De Marchi , Paresce , Straniero and Moroni ( 2003 ) on the white dwarf cooling age of M4 .
The authors question the data analysis and interpretation that led to the conclusions in Hansen et al .
( 2002 ) .
In their paper , De Marchi et al .
are unable to obtain photometry as deep as ours from the same data set and therefore assert that only a lower limit to the white dwarf cooling age for this cluster of \sim 9 Gyr can be obtained .

In this short contribution we show that shortcomings in the data analysis and reduction techniques of De Marchi et al .
are responsible for their inability to reach the photometry limits that our study reports .
In a forthcoming paper in which the complete techniques for age determination with white dwarfs are laid out , we demonstrate that their method of fitting the luminosity function gives a spuriously low white dwarf cooling age .