diff -NarU5 aumix-2.8.orig/src/common.c aumix-2.8/src/common.c
--- aumix-2.8.orig/src/common.c	2008-09-26 13:50:32.000000000 -0400
+++ aumix-2.8/src/common.c	2008-09-26 13:51:16.000000000 -0400
@@ -17,10 +17,11 @@
  * You should have received a copy of the GNU General Public License along with
  * aumix; if not, write to the Free Software Foundation, Inc., 59 Temple Place,
  * Suite 330, Boston, MA 02111-1307, USA.
  */
 
+#include <errno.h>
 #include "common.h"
 #ifdef HAVE_CURSES
 #include "curses.h"
 #include "gpm-xterm.h"
 #endif				/* HAVE_CURSES */
@@ -621,32 +622,33 @@
 }
 
 int             SetShowNoninter(int dev)
 {
 /* Change or display settings from the command line. */
-	char           *devstr, dest;
+	char           *devstr;
 	int             change = 0, tmp, left, right;
 	/* Increase or decrease levels, optionally by a number. */
-	if (!strncmp(optarg, "+", 1) || !strncmp(optarg, "-", 1)) {
+	if ((*optarg == '+') || (*optarg == '-')) {
 		ErrorExitWarn(ReadLevel(dev, &tmp), 'e');
 		right = tmp >> 8;	/* I'll take the high byte, */
 		left = tmp & 0xFF;	/* and you take the low byte. */
-		strncpy(&dest, (optarg + 1), 3);
-		change = 1;	/* For compatibility with versions 1.15 to 1.17, assume one if no number was given. */
-		if (atoi(&dest))
-			change = atoi(&dest);
-		if (*optarg == '+') {	/* increase */
-			right += change;
-			left += change;
-			right = (right > MAXLEVEL) ? MAXLEVEL : right;
-			left = (left > MAXLEVEL) ? MAXLEVEL : left;
-		} else {	/* decrease */
-			left -= change;
-			right -= change;
-			left = (left < 0) ? 0 : left;
-			right = (right < 0) ? 0 : right;
+
+		change = (int) strtol(optarg, NULL, 10);
+		if (change == 0 && *(optarg + 1) != '0') {
+			/* For compat. w. 1.15 - 1.17:
+			   assume 1 unless 0 given explicitly */
+			change = (*optarg == '+') ? 1 : -1;
 		}
+
+		right += change;
+		left += change;
+
+		if (right < 0) right = 0;
+		if (left < 0) left = 0;
+		if (right > MAXLEVEL) right = MAXLEVEL;
+		if (left > MAXLEVEL) left = MAXLEVEL;
+
 		tmp = left + (right << 8);
 		ErrorExitWarn(WriteLevel(dev, tmp), 'e');	/* Try to write new settings to the mixer. */
 		return 0;
 	}
 	if ((*optarg == 'R') || (*optarg == 'P')) {