diff --git a/ucloud/docs/source/hacking.rst b/ucloud/docs/source/hacking.rst
index 976970b..2df42a7 100644
--- a/ucloud/docs/source/hacking.rst
+++ b/ucloud/docs/source/hacking.rst
@@ -12,5 +12,6 @@ How to hack on the code.
 * git clone the repo
 * cd to the repo
 * Setup your venv: python -m venv venv
+* . ./venv/bin/activate # you need the leading dot for sourcing!
 * Run ./bin/ucloud-run-reinstall - it should print you an error
   message on how to use ucloud