diff --git a/src/buffer.c b/src/buffer.c
index 8b1bceb..e5d2dde 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -1412,7 +1412,7 @@
 # ifdef FEAT_AUTOCMD
 		   && !(curwin->w_closing || curwin->w_buffer->b_locked > 0)
 # endif
-		   && (firstwin != lastwin || first_tabpage->tp_next != NULL))
+		   && (!ONE_WINDOW || first_tabpage->tp_next != NULL))
 	{
 	    if (win_close(curwin, FALSE) == FAIL)
 		break;
@@ -5140,7 +5140,7 @@
 			: wp->w_width != Columns)
 		    || (had_tab > 0 && wp != firstwin)
 #endif
-		    ) && firstwin != lastwin
+		    ) && !ONE_WINDOW
 #ifdef FEAT_AUTOCMD
 		    && !(wp->w_closing || wp->w_buffer->b_locked > 0)
 #endif
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index cb58f24..206ead1 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -4577,7 +4577,7 @@
     if (eap->forceit)
 	bigness = curwin->w_height;
 #ifdef FEAT_WINDOWS
-    else if (firstwin != lastwin)
+    else if (!ONE_WINDOW)
 	bigness = curwin->w_height - 3;
 #endif
     else
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index dcb5cfe..9ad7d77 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -7488,9 +7488,9 @@
 {
     /* First close all the windows but the current one.  If that worked then
      * close the last window in this tab, that will close it. */
-    if (lastwin != firstwin)
+    if (!ONE_WINDOW)
 	close_others(TRUE, forceit);
-    if (lastwin == firstwin)
+    if (ONE_WINDOW)
 	ex_win_close(forceit, curwin, NULL);
 # ifdef FEAT_GUI
     need_mouse_correct = TRUE;
diff --git a/src/option.c b/src/option.c
index c32a2a4..ecfdc40 100644
--- a/src/option.c
+++ b/src/option.c
@@ -8551,7 +8551,7 @@
 	}
 
 	/* Change window height NOW */
-	if (lastwin != firstwin)
+	if (!ONE_WINDOW)
 	{
 	    if (pp == &p_wh && curwin->w_height < p_wh)
 		win_setheight((int)p_wh);
@@ -8591,7 +8591,7 @@
 	}
 
 	/* Change window width NOW */
-	if (lastwin != firstwin && curwin->w_width < p_wiw)
+	if (!ONE_WINDOW && curwin->w_width < p_wiw)
 	    win_setwidth((int)p_wiw);
     }
 
@@ -10075,7 +10075,7 @@
 comp_col(void)
 {
 #if defined(FEAT_CMDL_INFO) && defined(FEAT_WINDOWS)
-    int last_has_status = (p_ls == 2 || (p_ls == 1 && firstwin != lastwin));
+    int last_has_status = (p_ls == 2 || (p_ls == 1 && !ONE_WINDOW));
 
     sc_col = 0;
     ru_col = 0;
diff --git a/src/version.c b/src/version.c
index ef637a8..6d12500 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    73,
+/**/
     72,
 /**/
     71,
diff --git a/src/window.c b/src/window.c
index 17656d5..c4448b7 100644
--- a/src/window.c
+++ b/src/window.c
@@ -791,7 +791,7 @@
 	oldwin = curwin;
 
     /* add a status line when p_ls == 1 and splitting the first window */
-    if (lastwin == firstwin && p_ls == 1 && oldwin->w_status_height == 0)
+    if (ONE_WINDOW && p_ls == 1 && oldwin->w_status_height == 0)
     {
 	if (oldwin->w_height <= p_wmh && new_wp == NULL)
 	{
@@ -1492,7 +1492,7 @@
     win_T	*wp2;
     int		temp;
 
-    if (lastwin == firstwin)	    /* just one window */
+    if (ONE_WINDOW)	    /* just one window */
     {
 	beep_flush();
 	return;
@@ -1674,7 +1674,7 @@
     int		dir;
     int		height = curwin->w_height;
 
-    if (lastwin == firstwin)
+    if (ONE_WINDOW)
     {
 	beep_flush();
 	return;
@@ -2123,7 +2123,7 @@
 
     ++RedrawingDisabled;
 
-    for (wp = firstwin; wp != NULL && lastwin != firstwin; )
+    for (wp = firstwin; wp != NULL && !ONE_WINDOW; )
     {
 	if (wp->w_buffer == buf && (!keep_curwin || wp != curwin)
 #ifdef FEAT_AUTOCMD
@@ -3373,7 +3373,7 @@
 	}
     }
 
-    if (message && lastwin != firstwin)
+    if (message && !ONE_WINDOW)
 	EMSG(_("E445: Other window contains changes"));
 }
 
@@ -5971,7 +5971,7 @@
 {
     /* Don't make a difference between horizontal or vertical split. */
     last_status_rec(topframe, (p_ls == 2
-			  || (p_ls == 1 && (morewin || lastwin != firstwin))));
+			  || (p_ls == 1 && (morewin || !ONE_WINDOW))));
 }
 
     static void