diff --git a/README.md b/README.md
index 366727eee..2e63602d6 100644
--- a/README.md
+++ b/README.md
@@ -27,7 +27,7 @@ Please refer to the [installation documentation](doc/INSTALL.md) for detailed in
 For the impatient here's the gist of it for Ubuntu and Debian:
 
 ```
-sudo apt-get install -y autoconf automake build-essential git libtool libgmp-dev libsqlite3-dev python python3 net-tools
+sudo apt-get install -y autoconf automake build-essential git libtool libgmp-dev libsqlite3-dev python python3 net-tools libsodium-dev
 git clone https://github.com/ElementsProject/lightning.git
 cd lightning
 make
diff --git a/doc/INSTALL.md b/doc/INSTALL.md
index c6d20fa55..93d47490e 100644
--- a/doc/INSTALL.md
+++ b/doc/INSTALL.md
@@ -17,7 +17,7 @@ To Build on Ubuntu 15.10 or above
 
 Get dependencies:
 ```
-sudo apt-get install -y autoconf automake build-essential git libtool libgmp-dev libsqlite3-dev python python3 net-tools
+sudo apt-get install -y autoconf automake build-essential git libtool libgmp-dev libsqlite3-dev python python3 net-tools libsodium-dev
 ```
 
 If you don't have Bitcoin installed locally you'll need to install that as well: