diff --git a/src/libavrdude.h b/src/libavrdude.h
index 453b22a0..60cf4ebf 100644
--- a/src/libavrdude.h
+++ b/src/libavrdude.h
@@ -59,6 +59,7 @@ typedef uint32_t pinmask_t;
 #define LIBAVRDUDE_NOTSUPPORTED (-2) // operation not supported
 #define LIBAVRDUDE_SOFTFAIL (-3) // returned, eg, by avr_signature() if caller
                                  // might proceed with chip erase
+#define LIBAVRDUDE_EXIT (-4)     // End all operations in this session
 
 /* formerly lists.h */
 
diff --git a/src/wiring.c b/src/wiring.c
index caac6bbe..798db2a3 100644
--- a/src/wiring.c
+++ b/src/wiring.c
@@ -109,7 +109,7 @@ static int wiring_parseextparms(const PROGRAMMER *pgm, const LISTID extparms) {
       msg_error("  -xsnooze=<arg> Wait snooze [ms] before protocol sync after port open\n");
       msg_error("  -xdelay=<arg>  Add delay [ms] after reset, can be negative\n");
       msg_error("  -xhelp         Show this help menu and exit\n");
-      exit(0);
+      return LIBAVRDUDE_EXIT;;
     }
 
     pmsg_error("invalid extended parameter '%s'\n", extended_param);