diff --git a/Makefile b/Makefile
index 08d394c..23abcad 100644
--- a/Makefile
+++ b/Makefile
@@ -20,6 +20,9 @@ ELF := $(SRC:.c=.elf)
 
 all: $(ELF)
 
+sub:
+	@-find . -mindepth 1 -maxdepth 1 -type d -exec make --no-print-directory -C {} \;
+
 tags:
 	ctags -R .
 
@@ -32,5 +35,6 @@ format:
 clean:
 	@echo "Cleaning up..."
 	@rm -rf $(OBJ) $(ELF) *.json .cache
+	@find . -mindepth 1 -maxdepth 1 -type d -exec make --no-print-directory -C {} clean \;
 
 .PHONY: format