diff --git a/src/newgrf_config.cpp b/src/newgrf_config.cpp
--- a/src/newgrf_config.cpp
+++ b/src/newgrf_config.cpp
@@ -150,6 +150,8 @@ GRFConfig **CopyGRFConfigList(GRFConfig 
 			if (src->error->custom_message != NULL) c->error->custom_message = strdup(src->error->custom_message);
 		}
 
+		ClrBit(c->flags, GCF_COPY);
+
 		ClrBit(c->flags, GCF_INIT_ONLY);
 		if (init_only) SetBit(c->flags, GCF_INIT_ONLY);