diff --git a/src/ex_cmds2.c b/src/ex_cmds2.c
index 5a33bb1..66e5fca 100644
--- a/src/ex_cmds2.c
+++ b/src/ex_cmds2.c
@@ -1864,6 +1864,8 @@
     char_u	*p;
     int		old_arg_idx = curwin->w_arg_idx;
 
+    if (NOT_IN_POPUP_WINDOW)
+	return;
     if (argn < 0 || argn >= ARGCOUNT)
     {
 	if (ARGCOUNT <= 1)
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 82f9462..cc6a920 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -5452,6 +5452,8 @@
     static void
 ex_bunload(exarg_T *eap)
 {
+    if (NOT_IN_POPUP_WINDOW)
+	return;
     eap->errmsg = do_bufdel(
 	    eap->cmdidx == CMD_bdelete ? DOBUF_DEL
 		: eap->cmdidx == CMD_bwipeout ? DOBUF_WIPE
@@ -5466,6 +5468,8 @@
     static void
 ex_buffer(exarg_T *eap)
 {
+    if (NOT_IN_POPUP_WINDOW)
+	return;
     if (*eap->arg)
 	eap->errmsg = e_trailing;
     else
@@ -6768,6 +6772,9 @@
 		       || eap->cmdidx == CMD_tabfind
 		       || eap->cmdidx == CMD_tabnew;
 
+    if (NOT_IN_POPUP_WINDOW)
+	return;
+
 #ifdef FEAT_GUI
     need_mouse_correct = TRUE;
 #endif
@@ -6895,6 +6902,8 @@
 {
     int tab_number;
 
+    if (NOT_IN_POPUP_WINDOW)
+	return;
     switch (eap->cmdidx)
     {
 	case CMD_tabfirst:
@@ -7146,6 +7155,8 @@
     int		need_hide;
     int		exmode_was = exmode_active;
 
+    if (NOT_IN_POPUP_WINDOW)
+	return;
     /*
      * ":vi" command ends Ex mode.
      */
diff --git a/src/macros.h b/src/macros.h
index 8c0e04a..0f5ab77 100644
--- a/src/macros.h
+++ b/src/macros.h
@@ -339,3 +339,9 @@
 
 /* Wether a command index indicates a user command. */
 #define IS_USER_CMDIDX(idx) ((int)(idx) < 0)
+
+#ifdef FEAT_TEXT_PROP
+# define NOT_IN_POPUP_WINDOW not_in_popup_window()
+#else
+# define NOT_IN_POPUP_WINDOW 0
+#endif
diff --git a/src/popupwin.c b/src/popupwin.c
index 73b98be..2ebfda2 100644
--- a/src/popupwin.c
+++ b/src/popupwin.c
@@ -747,4 +747,16 @@
 # endif
     }
 }
+
+    int
+not_in_popup_window()
+{
+    if (bt_popup(curwin->w_buffer))
+    {
+	emsg(_("E994: Not allowed in a popup window"));
+	return TRUE;
+    }
+    return FALSE;
+}
+
 #endif // FEAT_TEXT_PROP
diff --git a/src/proto/popupwin.pro b/src/proto/popupwin.pro
index eb9e241..107a427 100644
--- a/src/proto/popupwin.pro
+++ b/src/proto/popupwin.pro
@@ -13,4 +13,5 @@
 void f_popup_move(typval_T *argvars, typval_T *rettv);
 void f_popup_getpos(typval_T *argvars, typval_T *rettv);
 void f_popup_getoptions(typval_T *argvars, typval_T *rettv);
+int not_in_popup_window(void);
 /* vim: set ft=c : */
diff --git a/src/testdir/test_popupwin.vim b/src/testdir/test_popupwin.vim
index d0d27b5..7c3cd94 100644
--- a/src/testdir/test_popupwin.vim
+++ b/src/testdir/test_popupwin.vim
@@ -108,8 +108,27 @@
 func Test_win_execute_closing_curwin()
   split
   let winid = popup_create('some text', {})
-  call win_execute(winid, winnr() .. "close")
-  call assert_equal(1, winnr())
+  call assert_fails('call win_execute(winid, winnr() .. "close")', 'E994')
+  popupclear
+endfunc
+
+func Test_win_execute_not_allowed()
+  let winid = popup_create('some text', {})
+  call assert_fails('call win_execute(winid, "split")', 'E994:')
+  call assert_fails('call win_execute(winid, "vsplit")', 'E994:')
+  call assert_fails('call win_execute(winid, "close")', 'E994:')
+  call assert_fails('call win_execute(winid, "bdelete")', 'E994:')
+  call assert_fails('call win_execute(winid, "tabnew")', 'E994:')
+  call assert_fails('call win_execute(winid, "tabnext")', 'E994:')
+  call assert_fails('call win_execute(winid, "next")', 'E994:')
+  call assert_fails('call win_execute(winid, "rewind")', 'E994:')
+  call assert_fails('call win_execute(winid, "buf")', 'E994:')
+  call assert_fails('call win_execute(winid, "edit")', 'E994:')
+  call assert_fails('call win_execute(winid, "enew")', 'E994:')
+  call assert_fails('call win_execute(winid, "wincmd x")', 'E994:')
+  call assert_fails('call win_execute(winid, "wincmd w")', 'E994:')
+  call assert_fails('call win_execute(winid, "wincmd t")', 'E994:')
+  call assert_fails('call win_execute(winid, "wincmd b")', 'E994:')
   popupclear
 endfunc
 
diff --git a/src/version.c b/src/version.c
index c7c19f3..4b380d2 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1438,
+/**/
     1437,
 /**/
     1436,
diff --git a/src/window.c b/src/window.c
index e73a9f4..42689ee 100644
--- a/src/window.c
+++ b/src/window.c
@@ -87,7 +87,8 @@
 #endif
     char_u	cbuf[40];
 
-    Prenum1 = Prenum == 0 ? 1 : Prenum;
+    if (NOT_IN_POPUP_WINDOW)
+	return;
 
 #ifdef FEAT_CMDWIN
 # define CHECK_CMDWIN \
@@ -102,6 +103,8 @@
 # define CHECK_CMDWIN do { /**/ } while (0)
 #endif
 
+    Prenum1 = Prenum == 0 ? 1 : Prenum;
+
     switch (nchar)
     {
 /* split current window in two parts, horizontally */
@@ -732,6 +735,9 @@
     int
 win_split(int size, int flags)
 {
+    if (NOT_IN_POPUP_WINDOW)
+	return FAIL;
+
     /* When the ":tab" modifier was used open a new tab page instead. */
     if (may_open_tabpage() == OK)
 	return OK;
@@ -1509,7 +1515,9 @@
     win_T	*wp2;
     int		temp;
 
-    if (ONE_WINDOW)	    /* just one window */
+    if (NOT_IN_POPUP_WINDOW)
+	return;
+    if (ONE_WINDOW)	    // just one window
     {
 	beep_flush();
 	return;
@@ -2363,6 +2371,9 @@
     tabpage_T   *prev_curtab = curtab;
     frame_T	*win_frame = win->w_frame->fr_parent;
 
+    if (NOT_IN_POPUP_WINDOW)
+	return FAIL;
+
     if (last_window())
     {
 	emsg(_("E444: Cannot close last window"));
@@ -4221,6 +4232,8 @@
     win_T	*owp = curwin;
 #endif
 
+    if (NOT_IN_POPUP_WINDOW)
+	return;
     if (text_locked())
     {
 	beep_flush();