diff --git a/README.md b/README.md
index 4a0bae205..3c89d4f7f 100644
--- a/README.md
+++ b/README.md
@@ -445,7 +445,7 @@ pip install cdisc-rules-engine
 
 For implementation instructions, see [PYPI.md](PYPI.md).
 
-### Cloning
+### Source Code
 
 In the terminal, navigate to the directory you intend to install CORE rules engine in
 
@@ -455,11 +455,16 @@ In the terminal, navigate to the directory you intend to install CORE rules engi
    git clone https://github.com/cdisc-org/cdisc-rules-engine
    ```
 
-2. Ensure you have Python 3.12 installed:
-   You can check your Python version with:
+2. **IMPORTANT: Python 3.12 is required**
+
+   CORE Rules Engine requires Python 3.12. Other versions are not supported and may cause unexpected errors or incorrect validation results.
+
+   Check your Python version:
+
    ```
    python --version
    ```
+
    If you don't have Python 3.12, please download and install it from [python.org](https://www.python.org/downloads/) or using your system's package manager.
 
 ### Installing dependencies