diff --git a/test/Makefile b/test/Makefile
index 100401f03954..ff4b7e1d45bd 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -12,7 +12,7 @@ all: clean deps $(T) aggregate
 
 clean:
 	@echo "*** $@ ***"
-	-rm -r test-results
+	-rm -rf test-results
 
 $(T):
 	@echo "*** $@ ***"