diff --git a/libraries/AP_Common/menu.cpp b/libraries/AP_Common/menu.cpp
index 7d30565c62..3c29258169 100644
--- a/libraries/AP_Common/menu.cpp
+++ b/libraries/AP_Common/menu.cpp
@@ -30,7 +30,8 @@ Menu::Menu(const prog_char *prompt, const Menu::command *commands, uint8_t entri
 void
 Menu::run(void)
 {
-    uint8_t		len, i, ret;
+    int8_t		ret;
+    uint8_t		len, i;
     uint8_t		argc;
     int			c;
     char		*s;
@@ -123,12 +124,12 @@ Menu::run(void)
                 return;
             }
         }
-        
+
         if (cmd_found==false)
         {
     		Serial.println("Invalid command, type 'help'");
     	}
-        	
+
     }
 }