diff --git a/README.md b/README.md
index 41d2894..452b81a 100644
--- a/README.md
+++ b/README.md
@@ -54,7 +54,12 @@ After adding the function, reload your shell configuration and run `get_idf` to
 
 ### Building
 
+**Note:** All `idf.py` commands require the ESP-IDF environment to be activated first by running `get_idf`.
+
 ```bash
+# Activate ESP-IDF environment (required before all idf.py commands)
+get_idf
+
 # Set target (e.g., esp32c5, esp32s3, esp32)
 idf.py set-target esp32c5