diff --git a/project/osforce.mk b/project/osforce.mk
index a2041ed..ea1eff2 100644
--- a/project/osforce.mk
+++ b/project/osforce.mk
@@ -4,9 +4,11 @@ endif
 
 config.tag:
 	mkdir -p build
-	cp -a $(PROJECT_DIR)/config/$(CFGHOST)/config.c   build/
-	cp -a $(PROJECT_DIR)/config/$(CFGHOST)/pyconfig.h build/
+	cp -p $(PROJECT_DIR)/config/$(CFGHOST)/config.c   build/
+	cp -p $(PROJECT_DIR)/config/$(CFGHOST)/pyconfig.h build/
 	touch config.tag
+	touch build/config.c
+	touch build/pyconfig.h
 
 clean-config:
 	rm -f config.tag