--- ray/src/px/clrtab.c	1993/05/05 10:18:05	2.6
+++ ray/src/px/clrtab.c	1993/06/10 15:45:18	2.7
@@ -238,7 +238,8 @@ int	p;
 register int	box[3][2];
 {
 	unsigned long	sum[3];
-	unsigned	r, g, n;
+	unsigned	r, g;
+	unsigned long	n;
 	register unsigned	b, c;
 						/* sum pixels in box */
 	n = 0;
@@ -254,7 +255,7 @@ register int	box[3][2];
 		    }
 		    histo[r][g][b] = p;		/* assign pixel */
 		}
-	if (n >= (1<<23)/HMAX) {		/* avoid overflow */
+	if (n >= (1L<<23)/HMAX) {		/* avoid overflow */
 		sum[RED] /= n;
 		sum[GRN] /= n;
 		sum[BLU] /= n;