diff --git a/Makefile b/Makefile
index f88ac9b..9379346 100644
--- a/Makefile
+++ b/Makefile
@@ -3,3 +3,8 @@ default: slides.md
 
 pdf: slides.md
 	marp --pdf slides.md
+
+clean:
+	rm -f slides.html slides.pdf
+
+PHONY: .clean