diff --git a/src/testdir/test_visual.vim b/src/testdir/test_visual.vim
index a187aa8e085e7..72f5388b934df 100644
--- a/src/testdir/test_visual.vim
+++ b/src/testdir/test_visual.vim
@@ -1318,5 +1318,15 @@ func Test_visual_block_insert_round_off()
   bwipe!
 endfunc
 
+" this was causing an ml_get error
+func Test_visual_exchange_windows()
+  enew!
+  new
+  call setline(1, ['foo', 'bar'])
+  exe "normal G\<C-V>gg\<C-W>\<C-X>OO\<Esc>"
+  bwipe!
+  bwipe!
+endfunc
+
 
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/version.c b/src/version.c
index 54a9ebee55c39..e32abbb79af82 100644
--- a/src/version.c
+++ b/src/version.c
@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4154,
 /**/
     4153,
 /**/
diff --git a/src/window.c b/src/window.c
index 05e85baf366a8..74257275c7c3a 100644
--- a/src/window.c
+++ b/src/window.c
@@ -1691,6 +1691,11 @@ win_exchange(long Prenum)
 
     (void)win_comp_pos();		// recompute window positions
 
+    if (wp->w_buffer != curbuf)
+	reset_VIsual_and_resel();
+    else if (VIsual_active)
+	wp->w_cursor = curwin->w_cursor;
+
     win_enter(wp, TRUE);
     redraw_all_later(NOT_VALID);
 }
@@ -5332,7 +5337,7 @@ frame_remove(frame_T *frp)
 win_alloc_lines(win_T *wp)
 {
     wp->w_lines_valid = 0;
-    wp->w_lines = ALLOC_CLEAR_MULT(wline_T, Rows );
+    wp->w_lines = ALLOC_CLEAR_MULT(wline_T, Rows);
     if (wp->w_lines == NULL)
 	return FAIL;
     return OK;