diff --git a/Master/rules.make b/Master/rules.make
index da882a47..1fb87b80 100644
--- a/Master/rules.make
+++ b/Master/rules.make
@@ -145,6 +145,7 @@ after-clean::
 before-distclean::
 
 internal-distclean::
+	rm -f core
 
 after-distclean::