diff --git a/src/testdir/test_autocmd.vim b/src/testdir/test_autocmd.vim
index 2df70b4..8103382 100644
--- a/src/testdir/test_autocmd.vim
+++ b/src/testdir/test_autocmd.vim
@@ -393,8 +393,8 @@
 
   let event = readfile('XscrollEvent')[0]->json_decode()
   call assert_equal({
-        \ 'all': {'leftcol': 1, 'topline': 0, 'width': 0, 'height': 0, 'skipcol': 0},
-        \ '1000': {'leftcol': -1, 'topline': 0, 'width': 0, 'height': 0, 'skipcol': 0}
+        \ 'all': {'leftcol': 1, 'topline': 0, 'topfill': 0, 'width': 0, 'height': 0, 'skipcol': 0},
+        \ '1000': {'leftcol': -1, 'topline': 0, 'topfill': 0, 'width': 0, 'height': 0, 'skipcol': 0}
         \ }, event)
 
   " Scroll up/down in Normal mode.
@@ -403,8 +403,8 @@
 
   let event = readfile('XscrollEvent')[0]->json_decode()
   call assert_equal({
-        \ 'all': {'leftcol': 0, 'topline': 1, 'width': 0, 'height': 0, 'skipcol': 0},
-        \ '1000': {'leftcol': 0, 'topline': -1, 'width': 0, 'height': 0, 'skipcol': 0}
+        \ 'all': {'leftcol': 0, 'topline': 1, 'topfill': 0, 'width': 0, 'height': 0, 'skipcol': 0},
+        \ '1000': {'leftcol': 0, 'topline': -1, 'topfill': 0, 'width': 0, 'height': 0, 'skipcol': 0}
         \ }, event)
 
   " Scroll up/down in Insert mode.
@@ -414,8 +414,8 @@
 
   let event = readfile('XscrollEvent')[0]->json_decode()
   call assert_equal({
-        \ 'all': {'leftcol': 0, 'topline': 1, 'width': 0, 'height': 0, 'skipcol': 0},
-        \ '1000': {'leftcol': 0, 'topline': -1, 'width': 0, 'height': 0, 'skipcol': 0}
+        \ 'all': {'leftcol': 0, 'topline': 1, 'topfill': 0, 'width': 0, 'height': 0, 'skipcol': 0},
+        \ '1000': {'leftcol': 0, 'topline': -1, 'topfill': 0, 'width': 0, 'height': 0, 'skipcol': 0}
         \ }, event)
 
   " Scroll the window horizontally to focus the last letter of the third line
@@ -427,8 +427,8 @@
 
   let event = readfile('XscrollEvent')[0]->json_decode()
   call assert_equal({
-        \ 'all': {'leftcol': 5, 'topline': 0, 'width': 0, 'height': 0, 'skipcol': 0},
-        \ '1000': {'leftcol': -5, 'topline': 0, 'width': 0, 'height': 0, 'skipcol': 0}
+        \ 'all': {'leftcol': 5, 'topline': 0, 'topfill': 0, 'width': 0, 'height': 0, 'skipcol': 0},
+        \ '1000': {'leftcol': -5, 'topline': 0, 'topfill': 0, 'width': 0, 'height': 0, 'skipcol': 0}
         \ }, event)
 
   " Ensure the command was triggered for the specified window ID.
@@ -582,6 +582,66 @@
   call StopVimInTerminal(buf)
 endfunc
 
+func Test_WinScrolled_diff()
+  CheckRunVimInTerminal
+
+  let lines =<< trim END
+    set diffopt+=foldcolumn:0
+    call setline(1, ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i'])
+    vnew
+    call setline(1, ['d', 'e', 'f', 'g', 'h', 'i'])
+    windo diffthis
+    func WriteScrollEvent()
+      call writefile([json_encode(v:event)], 'XscrollEvent')
+    endfunc
+    au WinScrolled * call WriteScrollEvent()
+  END
+  call writefile(lines, 'Xtest_winscrolled_diff', 'D')
+  let buf = RunVimInTerminal('-S Xtest_winscrolled_diff', {'rows': 8})
+
+  call term_sendkeys(buf, "\<C-E>")
+  call WaitForAssert({-> assert_match('^d', term_getline(buf, 3))}, 1000)
+
+  let event = readfile('XscrollEvent')[0]->json_decode()
+  call assert_equal({
+        \ 'all': {'leftcol': 0, 'topline': 1, 'topfill': 1, 'width': 0, 'height': 0, 'skipcol': 0},
+        \ '1000': {'leftcol': 0, 'topline': 1, 'topfill': 0, 'width': 0, 'height': 0, 'skipcol': 0},
+        \ '1001': {'leftcol': 0, 'topline': 0, 'topfill': -1, 'width': 0, 'height': 0, 'skipcol': 0}
+        \ }, event)
+
+  call term_sendkeys(buf, "2\<C-E>")
+  call WaitForAssert({-> assert_match('^f', term_getline(buf, 3))}, 1000)
+
+  let event = readfile('XscrollEvent')[0]->json_decode()
+  call assert_equal({
+        \ 'all': {'leftcol': 0, 'topline': 2, 'topfill': 2, 'width': 0, 'height': 0, 'skipcol': 0},
+        \ '1000': {'leftcol': 0, 'topline': 2, 'topfill': 0, 'width': 0, 'height': 0, 'skipcol': 0},
+        \ '1001': {'leftcol': 0, 'topline': 0, 'topfill': -2, 'width': 0, 'height': 0, 'skipcol': 0}
+        \ }, event)
+
+  call term_sendkeys(buf, "\<C-E>")
+  call WaitForAssert({-> assert_match('^g', term_getline(buf, 3))}, 1000)
+
+  let event = readfile('XscrollEvent')[0]->json_decode()
+  call assert_equal({
+        \ 'all': {'leftcol': 0, 'topline': 2, 'topfill': 0, 'width': 0, 'height': 0, 'skipcol': 0},
+        \ '1000': {'leftcol': 0, 'topline': 1, 'topfill': 0, 'width': 0, 'height': 0, 'skipcol': 0},
+        \ '1001': {'leftcol': 0, 'topline': 1, 'topfill': 0, 'width': 0, 'height': 0, 'skipcol': 0}
+        \ }, event)
+
+  call term_sendkeys(buf, "2\<C-Y>")
+  call WaitForAssert({-> assert_match('^e', term_getline(buf, 3))}, 1000)
+
+  let event = readfile('XscrollEvent')[0]->json_decode()
+  call assert_equal({
+        \ 'all': {'leftcol': 0, 'topline': 3, 'topfill': 1, 'width': 0, 'height': 0, 'skipcol': 0},
+        \ '1000': {'leftcol': 0, 'topline': -2, 'topfill': 0, 'width': 0, 'height': 0, 'skipcol': 0},
+        \ '1001': {'leftcol': 0, 'topline': -1, 'topfill': 1, 'width': 0, 'height': 0, 'skipcol': 0}
+        \ }, event)
+
+  call StopVimInTerminal(buf)
+endfunc
+
 func Test_WinClosed()
   " Test that the pattern is matched against the closed window's ID, and both
   " <amatch> and <afile> are set to it.