diff --git a/Readme.md b/Readme.md
index 24fa80b908079d358b704c685c82e4a40610d41a..f94a1bc3bf2b7bede9ff08ff80b5cb9c820c1348 100644
--- a/Readme.md
+++ b/Readme.md
@@ -85,3 +85,4 @@ Open three Terminals:
   * When that installation is ready type: 
   * `wget https://raw.githubusercontent.com/mavlink/mavros/master/mavros/scripts/install_geographiclib_datasets.sh`
   * `./install_geographiclib_datasets.sh` (you might have to make the install_geographiclib_datasets.sh executable.)
+## If roslaunch cannot find the python node, then you need to change permissions for all the python sources using chmod ##