diff --git a/doc/rjit/rjit.md b/doc/rjit/rjit.md
index 22cd54dc4c7337..273fdbeb9d5e14 100644
--- a/doc/rjit/rjit.md
+++ b/doc/rjit/rjit.md
@@ -1,7 +1,12 @@
-# RJIT
+# RJIT: Ruby JIT
 
 This document has some tips that might be useful when you work on RJIT.
 
+## Project purpose
+
+This project is for experimental purposes.
+For production deployment, consider using YJIT instead.
+
 ## Supported platforms
 
 The following platforms are assumed to work. `linux-x86_64` is tested on CI.