diff --git a/crates/lsp/src/lsp.rs b/crates/lsp/src/lsp.rs
index 9ff6e245c49d771c162ca55fa98bbd7ca37d7bd0..faa094153d4a26fb1a2b96360f2691989e81aad9 100644
--- a/crates/lsp/src/lsp.rs
+++ b/crates/lsp/src/lsp.rs
@@ -882,7 +882,9 @@ impl LanguageServer {
                 window: Some(WindowClientCapabilities {
                     work_done_progress: Some(true),
                     show_message: Some(ShowMessageRequestClientCapabilities {
-                        message_action_item: None,
+                        message_action_item: Some(MessageActionItemCapabilities {
+                            additional_properties_support: Some(true),
+                        }),
                     }),
                     ..WindowClientCapabilities::default()
                 }),