diff --git a/README.md b/README.md
index 70157ce..2fc51e5 100644
--- a/README.md
+++ b/README.md
@@ -96,6 +96,7 @@ python tts.py -v jf_alpha "言い習わし"
 For XPUs, we need to set some environmental variables. I have added a `intel-env.sh` script which will activate the conda environment `tts` and set the environmental variables.
 
 ```bash
+# Optional only, if using Intel XPU
 . intel-env.sh
 ```