1 files changed, 5 insertions, 1 deletions
diff --git a/root.sh b/root.sh
index 685e6036bc3a..203b6853d1c4 100644
--- a/root.sh
+++ b/root.sh
@@ -1,5 +1,9 @@
 if [ $PYTHONPATH ]; then
-    export PYTHONPATH=$PYTHONPATH:/usr/lib/root;
+    if [[ ":$PYTHONPATH:" == *":/usr/lib/root:"* ]]; then
+        return 0;
+    else
+        export PYTHONPATH=$PYTHONPATH:/usr/lib/root;
+    fi
 else
     export PYTHONPATH=/usr/lib/root;
 fi