diff --git a/ArduCopter/Log.pde b/ArduCopter/Log.pde
index 63cdcdbe7b7..2f7865335f5 100644
--- a/ArduCopter/Log.pde
+++ b/ArduCopter/Log.pde
@@ -77,7 +77,7 @@ dump_log(uint8_t argc, const Menu::arg *argv)
         cliSerial->printf_P(PSTR("dumping all\n"));
         Log_Read(0, 1, 0);
         return(-1);
-    } else if ((argc != 2) || (dump_log <= (last_log_num - DataFlash.get_num_logs())) || (dump_log > last_log_num)) {
+    } else if ((argc != 2) || ((uint16_t)dump_log <= (last_log_num - DataFlash.get_num_logs())) || (static_cast<uint16_t>(dump_log) > last_log_num)) {
         cliSerial->printf_P(PSTR("bad log number\n"));
         return(-1);
     }