diff --git a/Makefile b/Makefile
index 8f29aa8..ee84fbf 100644
--- a/Makefile
+++ b/Makefile
@@ -51,8 +51,8 @@ watchdog:
 
 # Remove artefacts
 clean:
-	rm -r cache
-	rm -r output/*.html
+	-rm -r cache
+	-rm -r output/*.html
 
 # Build everything from scratch and test functionality.
 test: clean all open server