diff --git a/README.md b/README.md
index d5a2741..a26253b 100644
--- a/README.md
+++ b/README.md
@@ -60,6 +60,7 @@ https://launchpad.net/~mraa/+archive/ubuntu/mraa
 
 ```bash
 sudo add-apt-repository ppa:mraa/mraa
+sudo apt-get update
 sudo apt-get install libmraa1 libmraa-dev mraa-tools python-mraa python3-mraa
 ```