diff --git a/system.c b/system.c
index 9079820..b8e2f6b 100644
--- a/system.c
+++ b/system.c
@@ -190,7 +190,7 @@ uint8_t system_execute_line(char *line)
             }
           } else { // Store global setting.
             if(!read_float(line, &char_counter, &value)) { return(STATUS_BAD_NUMBER_FORMAT); }
-            if(line[char_counter] != 0) { return(STATUS_INVALID_STATEMENT); }
+            if((line[char_counter] != 0) || (parameter > 255)) { return(STATUS_INVALID_STATEMENT); }
             return(settings_store_global_setting((uint8_t)parameter, value));
           }
       }