diff --git a/ale_linters/dafny/dafny.vim b/ale_linters/dafny/dafny.vim
index de7a7bb8..2a9f761a 100644
--- a/ale_linters/dafny/dafny.vim
+++ b/ale_linters/dafny/dafny.vim
@@ -16,7 +16,7 @@ function! ale_linters#dafny#dafny#Handle(buffer, lines) abort
 
     for l:match in ale#util#GetMatches(a:lines, '\v(.*)\((\d+),(\d+)\): (Verification of .{-} timed out after \d+ seconds)')
         call add(l:output, {
-        \     'bufnr': a:buffer,
+        \     'filename': l:match[1],
         \     'col': l:match[3] + 0,
         \     'lnum': l:match[2] + 0,
         \     'text': l:match[4],
diff --git a/test/handler/test_dafny_handler.vader b/test/handler/test_dafny_handler.vader
index 472615ac..4ca288d2 100644
--- a/test/handler/test_dafny_handler.vader
+++ b/test/handler/test_dafny_handler.vader
@@ -22,7 +22,7 @@ Execute(The Dafny handler should parse output correctly):
   \     'type': 'W'
   \   },
   \   {
-  \     'bufnr': 0,
+  \     'filename': 'File.dfy',
   \     'col': 45,
   \     'lnum': 123,
   \     'text': "Verification of 'Impl$$_22_Proof.__default.PutKeepsMapsFull' timed out after 2 seconds",