diff --git a/owlps-listener/owlps-listener.h b/owlps-listener/owlps-listener.h
index 2d30093..95c9ecb 100644
--- a/owlps-listener/owlps-listener.h
+++ b/owlps-listener/owlps-listener.h
@@ -87,6 +87,7 @@ enum {MODE_ACTIVE = 'a', MODE_PASSIVE = 'p', MODE_MIXED = 'm'} ;
 #define VERBOSE_INFO GET_VERBOSE() >= 2
 #define VERBOSE_CHATTERBOX GET_VERBOSE() >= 3
 #define VERBOSE_DISPLAY_CAPTURED GET_VERBOSE() >= 4
+#define MAX_VERBOSE_LEVEL 4
 
 
 /* Packet header sizes (in bytes) */
@@ -318,8 +319,12 @@ void print_version(void) ;
   (cfg_getfloat(cfg, "my_position_z"))
 #endif // OWLPS_LISTENER_USES_PTHREAD
 
-#define INCREMENT_VERBOSE() \
-  (cfg_setint(cfg, "verbose", cfg_getint(cfg, "verbose") + 1))
+#define INCREMENT_VERBOSE()                         \
+  do {                                              \
+    long vlevel = cfg_getint(cfg, "verbose") ;      \
+    if (vlevel < MAX_VERBOSE_LEVEL)                 \
+      cfg_setint(cfg, "verbose", vlevel + 1) ;      \
+  } while (0)
 #define RESET_VERBOSE() \
   (cfg_setint(cfg, "verbose", 0))
 #define GET_VERBOSE() \
@@ -430,8 +435,9 @@ void print_version(void) ;
   (options.my_position_z)
 #endif // OWLPS_LISTENER_USES_PTHREAD
 
-#define INCREMENT_VERBOSE() \
-  (++options.verbose)
+#define INCREMENT_VERBOSE()                         \
+  if (options.verbose < MAX_VERBOSE_LEVEL)          \
+    ++options.verbose
 #define RESET_VERBOSE() \
   (options.verbose = 0)
 #define GET_VERBOSE() \