Update quickstart.rst
diff --git a/docs/source/quickstart.rst b/docs/source/quickstart.rst
index 099afe5..3236a49 100644
--- a/docs/source/quickstart.rst
+++ b/docs/source/quickstart.rst
@@ -53,9 +53,12 @@
# make sure to change <directory_name> with the directory you created in step 2
# in this case it is caravel_tutorial
- export OPENLANE_ROOT=~/<directory_name>/openlane # you need to export this whenever you start a new shell
+ export OPENLANE_ROOT=~/<directory_name>/openlane # you need to export this whenever you start a new shell
export PDK_ROOT=~/<directory_name>/pdks # you need to export this whenever you start a new shell
+
+ # export the PDK variant depending on your shuttle, if you don't know leave it to the default
+ export PDK=sky130B
make setup
