diff --git a/runtime/lua/vim/diagnostic.lua b/runtime/lua/vim/diagnostic.lua
index bed91d3a1b..33d0be9e95 100644
--- a/runtime/lua/vim/diagnostic.lua
+++ b/runtime/lua/vim/diagnostic.lua
@@ -2600,16 +2600,17 @@ function M.match(str, pat, groups, severity_map, defaults)
     return
   end
 
-  local diagnostic = {}
+  local diagnostic = {} --- @type table<string,any>
 
   for i, match in ipairs(matches) do
     local field = groups[i]
     if field == 'severity' then
-      match = severity_map[match]
+      diagnostic[field] = severity_map[match]
     elseif field == 'lnum' or field == 'end_lnum' or field == 'col' or field == 'end_col' then
-      match = assert(tonumber(match)) - 1
+      diagnostic[field] = assert(tonumber(match)) - 1
+    elseif field then
+      diagnostic[field] = match
     end
-    diagnostic[field] = match --- @type any
   end
 
   diagnostic = vim.tbl_extend('keep', diagnostic, defaults or {}) --- @type vim.Diagnostic
diff --git a/runtime/lua/vim/treesitter/_fold.lua b/runtime/lua/vim/treesitter/_fold.lua
index 1064004320..8997341233 100644
--- a/runtime/lua/vim/treesitter/_fold.lua
+++ b/runtime/lua/vim/treesitter/_fold.lua
@@ -169,6 +169,7 @@ local function compute_folds_levels(bufnr, info, srow, erow, callback)
           -- If this line ends a fold f1 and starts a fold f2, then move f1's end to the previous line
           -- so that f2 gets the correct level on this line. This may reduce the size of f1 below
           -- foldminlines, but we don't handle it for simplicity.
+          --- @type integer avoid flaky error
           adjusted = level0 - leave_line
           leave_line = 0
         end