diff --git a/README.md b/README.md
index d7548bd8..a00a007d 100644
--- a/README.md
+++ b/README.md
@@ -111,7 +111,7 @@ Before Ubuntu 14.04:
 
 From Ubuntu 14.04:
 
-    sudo apt-get install libcurl4-openssl-dev libxml2 libxml2-dev libxslt1-dev ruby-dev build-essential
+    sudo apt-get install libcurl4-openssl-dev libxml2 libxml2-dev libxslt1-dev ruby-dev build-essential libgmp-dev
     git clone https://github.com/wpscanteam/wpscan.git
     cd wpscan
     sudo gem install bundler && bundle install --without test