autoload/lsp/diag.vim      |  2 +-
 autoload/lsp/lsp.vim       | 17 +++++++++++++++++
 autoload/lsp/lspserver.vim | 10 ++++++----
 plugin/lsp.vim             |  1 +
 test/clangd_tests.vim      | 25 +++++++++++++++++++++++++

diff --git a/autoload/lsp/diag.vim b/autoload/lsp/diag.vim
index 583c020664513b0e77a2592db5f7605fe59eb41a..263c07c8d35a826432362fb9a39f3c3f4c6bb59b 100644
--- a/autoload/lsp/diag.vim
+++ b/autoload/lsp/diag.vim
@@ -208,7 +208,7 @@ enddef
 
 # Refresh the placed diagnostics in buffer "bnr"
 # This inline signs, inline props, and virtual text diagnostics
-def DiagsRefresh(bnr: number)
+export def DiagsRefresh(bnr: number)
   :silent! bnr->bufload()
 
   RemoveDiagVisualsForBuffer(bnr)
diff --git a/autoload/lsp/lsp.vim b/autoload/lsp/lsp.vim
index 7b9ed6808a4182ab0b197e259a1cd2940ccc9e9c..66387ca3051a5e3b52c2bb8e62d8fe3d056181d0 100644
--- a/autoload/lsp/lsp.vim
+++ b/autoload/lsp/lsp.vim
@@ -529,6 +529,23 @@     buf.BufLspServerRemove(bnr, lspserver)
   endfor
 enddef
 
+# Buffer 'bnr' is loaded in a window, send the latest buffer contents to the
+# language servers.
+export def BufferLoadedInWin(bnr: number)
+  var lspservers: list<dict<any>> = buf.BufLspServersGet(bnr)
+  if lspservers->empty()
+    # No language servers for this buffer
+    return
+  endif
+  for lspserver in lspservers
+    if !lspserver->empty() && lspserver.ready
+      lspserver.textdocDidChange(bnr, 0, 0, 0, [])
+    endif
+  endfor
+  # Refresh the displayed diags visuals
+  diag.DiagsRefresh(bnr)
+enddef
+
 # Stop all the LSP servers
 export def StopAllServers()
   for lspserver in LSPServers
diff --git a/autoload/lsp/lspserver.vim b/autoload/lsp/lspserver.vim
index 4366d7334d95520d6b21d06640b5b29d48bc83af..4ae40198bd0045fb3dd480c22ad85f342bde307f 100644
--- a/autoload/lsp/lspserver.vim
+++ b/autoload/lsp/lspserver.vim
@@ -543,7 +543,8 @@   var params = {
     textDocument: {
       uri: util.LspBufnrToUri(bnr),
       languageId: ftype,
-      version: 1,
+      # Use Vim 'changedtick' as the LSP document version number
+      version: bnr->getbufvar('changedtick'),
       text: bnr->getbufline(1, '$')->join("\n") .. "\n"
     }
   }
@@ -570,7 +571,7 @@ 			changes: list<dict<number>>): void
   # Notification: 'textDocument/didChange'
   # Params: DidChangeTextDocumentParams
 
-  var changeset: list<dict<any>>
+  # var changeset: list<dict<any>>
 
   ##### FIXME: Sending specific buffer changes to the LSP server doesn't
   ##### work properly as the computed line range numbers is not correct.
@@ -608,14 +609,15 @@   #   var range: dict<dict<number>> = {'start': {'line': start_lnum, 'character': start_col}, 'end': {'line': end_lnum, 'character': end_col}}
   #   changeset->add({'range': range, 'text': lines})
   # endfor
 
-  changeset->add({text: bnr->getbufline(1, '$')->join("\n") .. "\n"})
   var params = {
     textDocument: {
       uri: util.LspBufnrToUri(bnr),
       # Use Vim 'changedtick' as the LSP document version number
       version: bnr->getbufvar('changedtick')
     },
-    contentChanges: changeset
+    contentChanges: [
+      {text: bnr->getbufline(1, '$')->join("\n") .. "\n"}
+    ]
   }
   lspserver.sendNotification('textDocument/didChange', params)
 enddef
diff --git a/plugin/lsp.vim b/plugin/lsp.vim
index 2de7df5b1bcd39d0171d92e3cec8433f860c3ffd..382ae49e49edcc5c925a008a6250c0e8a314a34c 100644
--- a/plugin/lsp.vim
+++ b/plugin/lsp.vim
@@ -49,6 +49,7 @@   autocmd BufNewFile,BufReadPost,FileType * lsp.AddFile(expand('<abuf>')->str2nr())
   # Note that when BufWipeOut is invoked, the current buffer may be different
   # from the buffer getting wiped out.
   autocmd BufWipeOut * lsp.RemoveFile(expand('<abuf>')->str2nr())
+  autocmd BufWinEnter * lsp.BufferLoadedInWin(expand('<abuf>')->str2nr())
 augroup END
 
 # TODO: Is it needed to shutdown all the LSP servers when exiting Vim?
diff --git a/test/clangd_tests.vim b/test/clangd_tests.vim
index 68d074bb1e1aa93f3f1f1432386abdb1a47a3da0..5ad93b7b3b1ab2bfc6200d20456fd3e1007b7708 100644
--- a/test/clangd_tests.vim
+++ b/test/clangd_tests.vim
@@ -1548,6 +1548,31 @@
   :%bw!
 enddef
 
+# Test for reloading a modified buffer with diags
+def g:Test_ReloadBufferWithDiags()
+  var lines: list<string> =<< trim END
+    void ReloadBufferFunc1(void)
+    {
+      int a:
+    }
+  END
+  writefile(lines, 'Xreloadbuffer.c')
+  :silent! edit Xreloadbuffer.c
+  g:WaitForServerFileLoad(1)
+  var signs = sign_getplaced('%', {group: '*'})[0].signs
+  assert_equal(3, signs[0].lnum)
+  append(0, ['', ''])
+  signs = sign_getplaced('%', {group: '*'})[0].signs
+  assert_equal(5, signs[0].lnum)
+  :edit!
+  sleep 200m
+  signs = sign_getplaced('%', {group: '*'})[0].signs
+  assert_equal(3, signs[0].lnum)
+
+  :%bw!
+  delete('Xreloadbuffer.c')
+enddef
+
 # Test for the :LspServer command.
 def g:Test_LspServer()
   new a.raku