diff --git a/documentation/en/default-lotus-config.toml b/documentation/en/default-lotus-config.toml
index cd9332356..eea9145bd 100644
--- a/documentation/en/default-lotus-config.toml
+++ b/documentation/en/default-lotus-config.toml
@@ -391,6 +391,7 @@
 
 
 [Index]
+  # EXPERIMENTAL FEATURE. USE WITH CAUTION
   # EnableMsgIndex enables indexing of messages on chain.
   #
   # type: bool
diff --git a/node/config/doc_gen.go b/node/config/doc_gen.go
index 26a254bad..79f2acef4 100644
--- a/node/config/doc_gen.go
+++ b/node/config/doc_gen.go
@@ -473,7 +473,8 @@ Set to 0 to keep all mappings`,
 			Name: "EnableMsgIndex",
 			Type: "bool",
 
-			Comment: `EnableMsgIndex enables indexing of messages on chain.`,
+			Comment: `EXPERIMENTAL FEATURE. USE WITH CAUTION
+EnableMsgIndex enables indexing of messages on chain.`,
 		},
 	},
 	"IndexProviderConfig": []DocField{
diff --git a/node/config/types.go b/node/config/types.go
index 5cbd21bf3..2de0c020e 100644
--- a/node/config/types.go
+++ b/node/config/types.go
@@ -736,6 +736,7 @@ type Events struct {
 }
 
 type IndexConfig struct {
+	// EXPERIMENTAL FEATURE. USE WITH CAUTION
 	// EnableMsgIndex enables indexing of messages on chain.
 	EnableMsgIndex bool
 }