diff --git a/crates/rust-analyzer/src/caps.rs b/crates/rust-analyzer/src/caps.rs
index ddee475040..17d0ed1b65 100644
--- a/crates/rust-analyzer/src/caps.rs
+++ b/crates/rust-analyzer/src/caps.rs
@@ -114,6 +114,7 @@ pub fn server_capabilities(config: &Config) -> ServerCapabilities {
         moniker_provider: None,
         experimental: Some(json!({
             "joinLines": true,
+            "openCargoToml": true,
             "ssr": true,
             "onEnter": true,
             "parentModule": true,
diff --git a/docs/dev/lsp-extensions.md b/docs/dev/lsp-extensions.md
index 78e14b01e4..5d98c0f099 100644
--- a/docs/dev/lsp-extensions.md
+++ b/docs/dev/lsp-extensions.md
@@ -619,6 +619,8 @@ Such actions on the client side are appended to a hover bottom as command links:
 
 **Issue:** https://github.com/rust-analyzer/rust-analyzer/issues/6462
 
+**Experimental Server Capability:** `{ "openCargoToml": boolean }`
+
 This request is sent from client to server to open the current project's Cargo.toml
 
 **Method:** `experimental/openCargoToml`