diff --git a/pylsp/lsp.py b/pylsp/lsp.py
index b82c72c5..f97a0a2e 100644
--- a/pylsp/lsp.py
+++ b/pylsp/lsp.py
@@ -48,6 +48,11 @@ class DiagnosticSeverity:
     Hint = 4
 
 
+class DiagnosticTag:
+    Unnecessary = 1
+    Deprecated = 2
+
+
 class InsertTextFormat:
     PlainText = 1
     Snippet = 2