diff --git a/src/nvim/diff.c b/src/nvim/diff.c
index 7096c5fa8a..0c59b8eb67 100644
--- a/src/nvim/diff.c
+++ b/src/nvim/diff.c
@@ -736,6 +736,12 @@ static void clear_diffout(diffout_T *dout)
 /// @return FAIL for failure.
 static int diff_write_buffer(buf_T *buf, mmfile_t *m, linenr_T start, linenr_T end)
 {
+  if (buf->b_ml.ml_flags & ML_EMPTY) {
+    m->ptr = NULL;
+    m->size = 0;
+    return OK;
+  }
+
   size_t len = 0;
 
   if (end < 0) {
diff --git a/test/functional/ui/diff_spec.lua b/test/functional/ui/diff_spec.lua
index bad35dd2af..8db6f776d1 100644
--- a/test/functional/ui/diff_spec.lua
+++ b/test/functional/ui/diff_spec.lua
@@ -614,6 +614,34 @@ int main(int argc, char **argv)
     ]])
   end)
 
+  it('Diff empty and non-empty file', function()
+    write_file(fname, '', false)
+    write_file(fname_2, 'foo\nbar\nbaz', false)
+    reread()
+
+    feed(':set diffopt=filler<cr>')
+    screen:expect([[
+      {7:  }{23:------------------}│{7:  }{22:foo              }|
+      {7:  }{23:------------------}│{7:  }{22:bar              }|
+      {7:  }{23:------------------}│{7:  }{22:baz              }|
+      {7:  }^                  │{1:~                  }|
+      {1:~                   }│{1:~                  }|*10
+      {3:<onal-diff-screen-1  }{2:<l-diff-screen-1.2 }|
+      :set diffopt=filler                     |
+    ]])
+
+    feed(':set diffopt+=internal<cr>')
+    screen:expect([[
+      {7:  }{23:------------------}│{7:  }{22:foo              }|
+      {7:  }{23:------------------}│{7:  }{22:bar              }|
+      {7:  }{23:------------------}│{7:  }{22:baz              }|
+      {7:  }^                  │{1:~                  }|
+      {1:~                   }│{1:~                  }|*10
+      {3:<onal-diff-screen-1  }{2:<l-diff-screen-1.2 }|
+      :set diffopt+=internal                  |
+    ]])
+  end)
+
   it('diffopt+=icase', function()
     write_file(fname, 'a\nb\ncd\n', false)
     write_file(fname_2, 'A\nb\ncDe\n', false)
diff --git a/test/functional/ui/highlight_spec.lua b/test/functional/ui/highlight_spec.lua
index 277bd96bd8..87d66fa604 100644
--- a/test/functional/ui/highlight_spec.lua
+++ b/test/functional/ui/highlight_spec.lua
@@ -596,13 +596,13 @@ describe('highlight', function()
     ]])
     screen:expect(
       [[
-      {1:  }^                       |
+      {1:  }{5:^                       }|
       {1:  }{2:01}{3:234 67}{2:89}{5:             }|
       {4:~                        }|*2
       {7:[No Name] [+]            }|
-      {1:  }                       |
       {1:  }{6:-----------------------}|
-      {4:~                        }|
+      {1:  }{6:-----------------------}|
+      {1:  }                       |
       {8:[No Name]                }|
                                |
     ]],
diff --git a/test/old/testdir/test_diffmode.vim b/test/old/testdir/test_diffmode.vim
index 31d66ebc4a..84cb7eb376 100644
--- a/test/old/testdir/test_diffmode.vim
+++ b/test/old/testdir/test_diffmode.vim
@@ -997,9 +997,17 @@ func Test_diff_screen()
   call WriteDiffFiles(buf, ['a ', 'x', 'cd', 'ef', 'xx  xx', 'foo', 'bar'], ['a', 'x', 'c d', ' ef', 'xx xx', 'foo', '', 'bar'])
   call VerifyInternal(buf, 'Test_diff_19', " diffopt+=iwhiteeol")
 
-  " Test 19: test diffopt+=iwhiteall
+  " Test 20: test diffopt+=iwhiteall
   call VerifyInternal(buf, 'Test_diff_20', " diffopt+=iwhiteall")
 
+  " Test 21: Delete all lines
+  call WriteDiffFiles(buf, [0], [])
+  call VerifyBoth(buf, "Test_diff_21", "")
+
+  " Test 22: Add line to empty file
+  call WriteDiffFiles(buf, [], [0])
+  call VerifyBoth(buf, "Test_diff_22", "")
+
   " clean up
   call StopVimInTerminal(buf)
   call delete('Xdifile1')