diff --git a/include/pocketpy/pocketpy.h b/include/pocketpy/pocketpy.h
index e99402f5..dff6af1d 100644
--- a/include/pocketpy/pocketpy.h
+++ b/include/pocketpy/pocketpy.h
@@ -90,7 +90,8 @@ enum py_CompileMode { EXEC_MODE, EVAL_MODE, SINGLE_MODE };
 
 /// Initialize pocketpy and the default VM.
 PK_API void py_initialize();
-/// Finalize pocketpy and free all VMs.
+/// Finalize pocketpy and free all VMs. This opearation is irreversible.
+/// After this call, you cannot use any function from this header anymore.
 PK_API void py_finalize();
 /// Get the current VM index.
 PK_API int py_currentvm();