diff --git a/doc/build-unix.md b/doc/build-unix.md
index d3a0536b10..d31382eb74 100644
--- a/doc/build-unix.md
+++ b/doc/build-unix.md
@@ -65,6 +65,10 @@ for Ubuntu 12.04 and later:
 	sudo apt-get install libboost-all-dev
 
  db4.8 packages are available [here](https://launchpad.net/~bitcoin/+archive/bitcoin).
+ You can add the repository using the following command:
+
+        sudo add-apt-repository ppa:bitcoin/bitcoin
+        sudo apt-get update
 
  Ubuntu 12.04 and later have packages for libdb5.1-dev and libdb5.1++-dev,
  but using these will break binary wallet compatibility, and is not recommended.