diff --git a/src/ex_cmds2.c b/src/ex_cmds2.c
index cb04635..89effa1 100644
--- a/src/ex_cmds2.c
+++ b/src/ex_cmds2.c
@@ -2041,7 +2041,7 @@
 }
 
 /*
- * flush all buffers, except the ones that are readonly
+ * Flush all buffers, except the ones that are readonly or are never written.
  */
     void
 autowrite_all(void)
@@ -2051,7 +2051,7 @@
     if (!(p_aw || p_awa) || !p_write)
 	return;
     FOR_ALL_BUFFERS(buf)
-	if (bufIsChanged(buf) && !buf->b_p_ro)
+	if (bufIsChanged(buf) && !buf->b_p_ro && !bt_dontwrite(buf))
 	{
 	    bufref_T	bufref;
 
diff --git a/src/testdir/test_writefile.vim b/src/testdir/test_writefile.vim
index 672ddd3..8e621b3 100644
--- a/src/testdir/test_writefile.vim
+++ b/src/testdir/test_writefile.vim
@@ -112,3 +112,41 @@
     throw 'Skipped: /dev/stdout is not writable'
   endif
 endfunc
+
+func Test_writefile_autowrite()
+  set autowrite
+  new
+  next Xa Xb Xc
+  call setline(1, 'aaa')
+  next
+  call assert_equal(['aaa'], readfile('Xa'))
+  call setline(1, 'bbb')
+  call assert_fails('edit XX')
+  call assert_false(filereadable('Xb'))
+
+  set autowriteall
+  edit XX
+  call assert_equal(['bbb'], readfile('Xb'))
+
+  bwipe!
+  call delete('Xa')
+  call delete('Xb')
+  set noautowrite
+endfunc
+
+func Test_writefile_autowrite_nowrite()
+  set autowrite
+  new
+  next Xa Xb Xc
+  set buftype=nowrite
+  call setline(1, 'aaa')
+  let buf = bufnr('%')
+  " buffer contents silently lost
+  edit XX
+  call assert_false(filereadable('Xa'))
+  rewind
+  call assert_equal('', getline(1))
+
+  bwipe!
+  set noautowrite
+endfunc
diff --git a/src/version.c b/src/version.c
index c2f64d3..db1f8e2 100644
--- a/src/version.c
+++ b/src/version.c
@@ -795,6 +795,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    334,
+/**/
     333,
 /**/
     332,