--- a/test/Makefile	Mon Dec 04 21:51:02 2017 +0100
+++ b/test/Makefile	Tue Dec 05 11:11:50 2017 +0100
@@ -119,6 +119,8 @@
   MKDIR=mkdir
   MV=mv
   HEAD=head
+  # Make it possible to override variables passed on the command line
+  unexport MAKEFLAGS
 
   jtreg_tests:
 	cd $(TOPDIR) && \