--- a/src/invlib.c.orig	2006-11-11 01:39:19.000000000 +0100
+++ b/src/invlib.c	2006-11-11 01:39:09.000000000 +0100
@@ -170,7 +170,7 @@
 
 	/* set up as though a block had come and gone, i.e., set up for new block  */
 	/* FIXME HBB: magic number alert (16) */
-	amtused = 16; /* leave no space - init 3 words + one for luck */
+	amtused = 4 * sizeof(long); /* leave no space - init 3 words + one for luck */
 	numinvitems = 0;
 	numlogblk = 0;
 	lastinblk = sizeof(t_logicalblk);
@@ -436,7 +436,7 @@
 	    invcannotwrite(indexfile);
 	    return(0);
 	}
-	amtused = 16;
+	amtused = 4 * sizeof(long);
 	numlogblk++;
 	/* check if had to back up, if so do it */
 	if (backupflag) {
@@ -467,7 +467,7 @@
 	    while (tptr3 > tptr)
 		*--tptr2 = *--tptr3;
 	    lastinblk -= j;
-	    amtused += (8 * backupflag + j);
+	    amtused += (2 * sizeof(long) * backupflag + j);
 	    for (i = 3; i < (backupflag * 2 + 2); i += 2) {
 		iteminfo.packword[0] = logicalblk.invblk[i];
 		iteminfo.e.offset += (tptr2 - tptr3);