diff --git a/README.md b/README.md
index 4345703..d9fd70e 100644
--- a/README.md
+++ b/README.md
@@ -67,6 +67,7 @@ docker run --gpus all -p 8880:8880 ghcr.io/remsky/kokoro-fastapi-gpu:v0.2.0post3
 
 1. Install prerequisites ():
    - Install [astral-uv](https://docs.astral.sh/uv/)
+   - Install [espeak-ng](https://github.com/espeak-ng/espeak-ng) in your system if you want it available as a fallback for unknown words/sounds. The upstream libraries may attempt to handle this, but results have varied.
    - Clone the repository:
         ```bash
         git clone https://github.com/remsky/Kokoro-FastAPI.git