diff --git a/scripts/macOS/setupHoudini.sh b/scripts/macOS/setupHoudini.sh
index 6bfc563..9461a5a 100644
--- a/scripts/macOS/setupHoudini.sh
+++ b/scripts/macOS/setupHoudini.sh
@@ -1,6 +1,6 @@
 omr_install_dir=/Applications/MoonRay/installs/openmoonray
 
-# save/restore PYTHONPATH, since Houdini seems to reject python3.9
+# save/restore PYTHONPATH, since Houdini supplies its own Python runtime
 OLDPP=${PYTHONPATH}
 source ${omr_install_dir}/scripts/setup.sh
 export PYTHONPATH=${OLDPP}
@@ -17,4 +17,4 @@ export PXR_PLUGINPATH_NAME=${omr_install_dir}/plugin/pxr
 # export HOUDINI_PACKAGE_VERBOSE=1
 
 export HOUDINI_OTLSCAN_PATH="${omr_install_dir}/plugin/houdini/otls:&"
-export HOUDINI_PATH="${omr_install_dir}/houdini/:${omr_install_dir}/plugin/houdini:&"
\ No newline at end of file
+export HOUDINI_PATH="${omr_install_dir}/houdini/:${omr_install_dir}/plugin/houdini:&"
diff --git a/scripts/setup.sh b/scripts/setup.sh
index c56faf6..3fc013c 100644
--- a/scripts/setup.sh
+++ b/scripts/setup.sh
@@ -25,8 +25,9 @@ echo "Setting up release in ${omr_root}"
 # NB required for Arras to function (it needs to find execComp)
 export PATH=${omr_root}/bin:${PATH}
 
-# need python modules for the USD interface and for the RATS tests
-export PYTHONPATH=${install_root}/lib/python:/usr/local/lib/python:${install_root}/lib64/python3.9/site-packages/:${PYTHONPATH}
+# Need Python modules for the USD interface and the RATS tests.  The macOS
+# Houdini build installs its bindings for Python 3.13.
+export PYTHONPATH=${omr_root}/python/lib/python3.13:${install_root}/lib/python3.13/site-packages:${install_root}/lib/python:${install_root}/lib64/python3.9/site-packages:/usr/local/lib/python:${PYTHONPATH}
 
 
 # tell moonray where to find dsos