diff --git a/crates/loro-wasm/.cargo/config.toml b/crates/loro-wasm/.cargo/config.toml
index 31af7dff..e841c735 100644
--- a/crates/loro-wasm/.cargo/config.toml
+++ b/crates/loro-wasm/.cargo/config.toml
@@ -1,5 +1,7 @@
 [profile.release]
 lto = true
 opt-level = "s"
+# Debug info only takes 4KB after gzipped, which is only 1% of the binary size.
+# But it's valuable for debugging.
 debug = true
 codegen-units = 1