diff --git a/stm-firmware/Makefile b/stm-firmware/Makefile
index 8eac35f..9464635 100644
--- a/stm-firmware/Makefile
+++ b/stm-firmware/Makefile
@@ -109,7 +109,9 @@ mrproper: clean
 
 clean:
 	@echo "Cleaning up derived files..."
-	$(QUIET)rm -f $(target).elf $(target).bin $(target).hex $(OBJ) $(ASOBJ) $(mapfile).map $(CFILES:%.c=$(OBJDIR)/%.c.d) $(ASFILES:%.S=$(OBJDIR)/%.S.d)
+	$(QUIET)rm -f $(target).elf $(target).bin $(target).hex $(OBJ) $(ASOBJ) $(mapfile).map $(CFILES:%.c=$(OBJDIR)/%.c.d) $(ASFILES:%.S=$(OBJDIR)/%.S.d) 
+	$(QUIET)rm -rf $(OBJDIR)/*
+
 qtproject:
 	echo -e "TEMPLATE = app\nCONFIG -= console app_bundle qt" > $(target).pro
 	echo -e "SOURCES += $(CFILES) $(ASFILES)" >> $(target).pro