diff --git a/Makefile b/Makefile
index 05bca0e..ccbb8d6 100644
--- a/Makefile
+++ b/Makefile
@@ -28,8 +28,9 @@ release: bin bindata.go
 docs: readme
 	cd www && hugo -d ../docs
 
-readme: www/data
-	cat README.md | python -c 'import json,sys; print(json.dumps({"content": sys.stdin.read()}))' > www/data/readme.json
+readme: www/data/readme.json
 
+www/data/readme.json: www/data README.md
+	cat README.md | python -c 'import json,sys; print(json.dumps({"content": sys.stdin.read()}))' > www/data/readme.json
 www/data bin:
 	mkdir -p $@