diff --git a/docs/development.rst b/docs/development.rst
--- a/docs/development.rst
+++ b/docs/development.rst
@@ -62,6 +62,40 @@ 4. Install required packages in the virt
workon conntrackt && pip install -r ~/projects/conntrackt/requirements/development.txt
+5. Download and unpack `Mozilla Firefox
+ `_ version **57.0.x** for
+ your platform into directory ``test_binaries/``. If using 64-bit
+ GNU/Linux distribution, this should be as easy as:
+
+ .. warning::
+ In order to ensure the functional tests run well, it is
+ important to use correct combination of geckodriver and Mozilla
+ Firefox.
+
+ ::
+
+ workon conntrackt && \
+ cd test_binaries/ && \
+ wget 'https://ftp.mozilla.org/pub/firefox/releases/57.0.2/linux-x86_64/en-US/firefox-57.0.2.tar.bz2' && \
+ tar xjf firefox-57.0.2.tar.bz2
+
+6. Download `geckodriver
+ `_ version
+ **v0.19.1**. If using 64-bit GNU/Linux distribution, this should be
+ as easy as:
+
+ .. warning::
+ In order to ensure the functional tests run well, it is
+ important to use correct combination of geckodriver and Mozilla
+ Firefox.
+
+ ::
+
+ workon conntrackt && \
+ cd test_binaries/ && \
+ wget 'https://github.com/mozilla/geckodriver/releases/download/v0.19.1/geckodriver-v0.19.1-linux64.tar.gz' && \
+ tar xzf geckodriver-v0.19.1-linux64.tar.gz
+
Development/test Django project
-------------------------------