diff --git a/common/common.h b/common/common.h
index 08e464e..c98b000 100644
--- a/common/common.h
+++ b/common/common.h
@@ -6,10 +6,10 @@
 ; to be able to recognize an overflow/underflow situation, rescale the arguments, and repeat the
 ; calculation.
 
-; Largest value:              $3fffffff or  1048575.999(9)
-; Smallest value:             $c0000001 or -1048575.999(0)
+; Largest value:              $3fffffff or  1048575.999(5)
+; Smallest value:             $c0000001 or -1048575.998(5) <- note 998(5)
 ; Largest value for DEC/HEX:  $3d08ffff or   999999.999(5)
-; Smallest value for DEC/HEX: $c2f70001 or  -999999.999(0)
+; Smallest value for DEC/HEX: $c2f70000 or  -999999.999(5)
 
 ; Instructions
 
diff --git a/xa-pre-process/main.c b/xa-pre-process/main.c
index 7e2609b..ad4d7e8 100644
--- a/xa-pre-process/main.c
+++ b/xa-pre-process/main.c
@@ -23,7 +23,7 @@ int main(int argc, char **argv)
 			int i;
 			for (i = 0; i < count; ++i)
 			{
-				int j;
+				int j, sign;
 				unsigned long working;
 				const char *s = "", *p, *q;
 				switch (tokens[i].type)
@@ -37,8 +37,14 @@ int main(int argc, char **argv)
 						yyin = fmemopen((void *)p, q - p, "r");
 						yyparse();
 						fclose(yyin);
-						/* Output */
+						/* Round towards ± infinity */
+						sign = result < 0? -1: +1;
+						if (sign < 0) result = -result;
+						result += 1 << (INT_FRAC - EXP_FRAC - 1);
+						if (sign < 0) result = -result;
+						/* Normalize */
 						working = (unsigned long)((result >> (INT_FRAC - EXP_FRAC)) % (1 << EXP_FULL));
+						/* Output in .BYTE format */
 						for (j = 0; j < EXP_FULL; j += CHAR_BIT)
 						{
 							printf("%s$%02lX", s, working & 0xff);