diff --git a/Makefile b/Makefile
index 0973f9d..3b6c1bd 100644
--- a/Makefile
+++ b/Makefile
@@ -114,7 +114,7 @@ all: $(BUILD)
 #-------------------------------------------------------------------------------
 
 $(BUILD):
-	@[ -d $@ ] || mkdir -p $@
+	@$(shell [ ! -d $(BUILD) ] && mkdir -p $(BUILD))
 	@$(MAKE) --no-print-directory -C $(BUILD) -f $(CURDIR)/Makefile
 
 #-------------------------------------------------------------------------------