diff --git a/config.def.h b/config.def.h
index 541293b..eb569b2 100644
--- a/config.def.h
+++ b/config.def.h
@@ -1,5 +1,6 @@
 /* See LICENSE file for copyright and license details. */
 
+/* The three fields set to 0 have to stay that way for a scalable font */
 static char font[] = "-*-dejavu sans condensed-bold-r-*-*-0-0-*-*-*-0-*-*";
 #define NUMFONTS 30
 #define FONTSZ(x) ((int)(100.0 * powf(1.1288, (x)))) /* x in [0, NUMFONTS-1] */