diff --git a/docs/Software_installation.md b/docs/Software_installation.md
index b1eaba95bfdddd901cd42d0679cd0c6f4f724452..9578aa7d03488f6a71ae716803a8bc497af86030 100644
--- a/docs/Software_installation.md
+++ b/docs/Software_installation.md
@@ -114,7 +114,7 @@ mv /home/u035/project/software/install/1000G_phase3_hg38/1000g.phase3.100k.b38*
 
 ## Python modules
 
-Users should include this line in any shell scripts requiring these modules:
+Users should include this line in any shell scripts requiring these modules, and ensure this command is run prior to installing any Python modules in this location.
 
 ```
 export PYTHONPATH=/home/u035/project/software/lib/python3.6/site-packages