added missing dependencies for Debian-based systems
diff --git a/INSTALL.Unix.md b/INSTALL.Unix.md
index bfd9c89..f0baf58 100644
--- a/INSTALL.Unix.md
+++ b/INSTALL.Unix.md
@@ -74,6 +74,9 @@
 
     sudo apt-get --no-install-recommends -y install \
         python-sphinx
+        
+    sudo pip install --upgrade sphinx_rtd_theme nose requests hypothesis
+
 
 Be sure to update the version numbers to match your system's available
 packages.