diff --git a/Makefile b/Makefile
index 90599816f..cc0b737f3 100644
--- a/Makefile
+++ b/Makefile
@@ -113,6 +113,7 @@ doc:
 %/:
 	mkdir -p $@
 
+.PRECIOUS: %/
 .SECONDEXPANSION:
 
 -include $(wildcard $(BUILDDIR)/**/*.d)