diff --git a/src/evalwindow.c b/src/evalwindow.c
index c7a9f79..534a047 100644
--- a/src/evalwindow.c
+++ b/src/evalwindow.c
@@ -810,7 +810,8 @@
     targetwin = find_win_by_nr_or_id(&argvars[1]);
 
     if (wp == NULL || targetwin == NULL || wp == targetwin
-	    || !win_valid(wp) || !win_valid(targetwin))
+	    || !win_valid(wp) || !win_valid(targetwin)
+	    || win_valid_popup(wp) || win_valid_popup(targetwin))
     {
         emsg(_(e_invalwindow));
 	rettv->vval.v_number = -1;
diff --git a/src/testdir/test_popupwin.vim b/src/testdir/test_popupwin.vim
index 9cd6e32..478e9d4 100644
--- a/src/testdir/test_popupwin.vim
+++ b/src/testdir/test_popupwin.vim
@@ -3307,4 +3307,16 @@
   set signcolumn&
 endfunc
 
+func Test_popupwin_splitmove()
+  vsplit
+  let win2 = win_getid()
+  let popup_winid = popup_dialog('hello', {})
+  call assert_fails('call win_splitmove(popup_winid, win2)', 'E957:')
+  call assert_fails('call win_splitmove(win2, popup_winid)', 'E957:')
+
+  call popup_clear()
+  bwipe
+endfunc
+
+
 " vim: shiftwidth=2 sts=2
diff --git a/src/version.c b/src/version.c
index 986a29f..a6112ce 100644
--- a/src/version.c
+++ b/src/version.c
@@ -739,6 +739,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    422,
+/**/
     421,
 /**/
     420,