diff --git a/helix-lsp/src/client.rs b/helix-lsp/src/client.rs
index 2f5b498d4..46772dd22 100644
--- a/helix-lsp/src/client.rs
+++ b/helix-lsp/src/client.rs
@@ -329,6 +329,10 @@ impl Client {
                                 ],
                             }),
                             insert_replace_support: Some(true),
+                            deprecated_support: Some(true),
+                            tag_support: Some(lsp::TagSupport {
+                                value_set: vec![lsp::CompletionItemTag::DEPRECATED],
+                            }),
                             ..Default::default()
                         }),
                         completion_item_kind: Some(lsp::CompletionItemKindCapability {
diff --git a/helix-term/src/ui/completion.rs b/helix-term/src/ui/completion.rs
index ac434894a..3e2f2aea4 100644
--- a/helix-term/src/ui/completion.rs
+++ b/helix-term/src/ui/completion.rs
@@ -1,6 +1,10 @@
 use crate::compositor::{Component, Context, Event, EventResult};
-use helix_view::{editor::CompleteAction, ViewId};
-use tui::buffer::Buffer as Surface;
+use helix_view::{
+    editor::CompleteAction,
+    theme::{Modifier, Style},
+    ViewId,
+};
+use tui::{buffer::Buffer as Surface, text::Span};
 
 use std::borrow::Cow;
 
@@ -33,8 +37,19 @@ impl menu::Item for CompletionItem {
     }
 
     fn format(&self, _data: &Self::Data) -> menu::Row {
+        let deprecated = self.deprecated.unwrap_or_default()
+            || self.tags.as_ref().map_or(false, |tags| {
+                tags.contains(&lsp::CompletionItemTag::DEPRECATED)
+            });
         menu::Row::new(vec![
-            menu::Cell::from(self.label.as_str()),
+            menu::Cell::from(Span::styled(
+                self.label.as_str(),
+                if deprecated {
+                    Style::default().add_modifier(Modifier::CROSSED_OUT)
+                } else {
+                    Style::default()
+                },
+            )),
             menu::Cell::from(match self.kind {
                 Some(lsp::CompletionItemKind::TEXT) => "text",
                 Some(lsp::CompletionItemKind::METHOD) => "method",