diff --git a/src/openttd.cpp b/src/openttd.cpp
--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -667,7 +667,7 @@ int openttd_main(int argc, char *argv[])
 			goto exit_noshutdown;
 		}
 		case 'G': scanner->generation_seed = atoi(mgo.opt); break;
-		case 'c': _config_file = stredup(mgo.opt); break;
+		case 'c': free(_config_file); _config_file = stredup(mgo.opt); break;
 		case 'x': scanner->save_config = false; break;
 		case 'h':
 			i = -2; // Force printing of help.