diff --git a/docs/server/source/quickstart.md b/docs/server/source/quickstart.md
index 2eae07f0..5c2b0500 100644
--- a/docs/server/source/quickstart.md
+++ b/docs/server/source/quickstart.md
@@ -8,7 +8,7 @@ A. Install MongoDB as the database backend. (There are other options but you can
 
 B. Run MongoDB. Open a Terminal and run the command:
 ```text
-$ mongod --replSet=bigchain-rs
+$ sudo mongod --replSet=bigchain-rs
 ```
 
 C. Ubuntu 16.04 already has Python 3.5, so you don't need to install it, but you do need to install some other things: