diff --git a/ocaml-lsp-server/src/code_actions/action_type_annotate.ml b/ocaml-lsp-server/src/code_actions/action_type_annotate.ml
index 62cb57e6f..8697c9394 100644
--- a/ocaml-lsp-server/src/code_actions/action_type_annotate.ml
+++ b/ocaml-lsp-server/src/code_actions/action_type_annotate.ml
@@ -4,25 +4,29 @@ open Fiber.O
 let action_kind = "type-annotate"
 
 let check_typeable_context pipeline pos_start =
+  let open Typedtree in
   let pos_start = Mpipeline.get_lexing_pos pipeline pos_start in
   let typer = Mpipeline.typer_result pipeline in
   let browse = Mbrowse.of_typedtree (Mtyper.get_typedtree typer) in
   let is_exp_constrained = function
-    | Typedtree.Texp_constraint _, _, _ -> true
-    | Typedtree.Texp_coerce (Some _, _), _, _ -> true
+    | Texp_constraint _, _, _ -> true
+    | Texp_coerce (Some _, _), _, _ -> true
     | _ -> false
   in
   let is_pat_constrained = function
-    | Typedtree.Tpat_constraint _, _, _ -> true
+    | Tpat_constraint _, _, _ -> true
     | _ -> false
   in
   let is_valid p extras =
     if List.exists ~f:p extras then `Invalid else `Valid
   in
   match Mbrowse.enclosing pos_start [ browse ] with
+  | (_, Pattern { pat_desc = Tpat_var _; _})
+    :: (_, Value_binding { vb_expr = { exp_desc = Texp_function _; _} ; _ })
+    :: _ -> `Invalid (* TODO: traverse function arguments *)
   | (_, Expression e) :: _ -> is_valid is_exp_constrained e.exp_extra
-  | (_, Pattern { pat_desc = Typedtree.Tpat_any; _ })
-    :: (_, Pattern { pat_desc = Typedtree.Tpat_alias _; pat_extra; _ })
+  | (_, Pattern { pat_desc = Tpat_any; _ })
+    :: (_, Pattern { pat_desc = Tpat_alias _; pat_extra; _ })
     :: _ -> is_valid is_pat_constrained pat_extra
   | (_, Pattern p) :: _ -> is_valid is_pat_constrained p.pat_extra
   | _ :: _ | [] -> `Invalid