diff --git a/src/terminal.go b/src/terminal.go
index 66bef46f..8e4968ef 100644
--- a/src/terminal.go
+++ b/src/terminal.go
@@ -1717,11 +1717,13 @@ func (t *Terminal) separatedByBorder() bool {
 	if t.inputBorderShape.Visible() {
 		return true
 	}
-	if t.previewOpts.position == posNext {
-		// A preview window at 'next' position sits right next to the input
-		// section instead. Keep the separator, as the visibility and the
-		// border of the preview window can change at runtime.
-		return false
+	for po := &t.previewOpts; po != nil; po = po.alternative {
+		if po.position == posNext {
+			// A preview window at 'next' position sits right next to the input
+			// section instead. Keep the separator, as the visibility and the
+			// border of the preview window can change at runtime.
+			return false
+		}
 	}
 	hasHeaderLinesWindow, headerLinesShape := t.determineHeaderLinesShape()
 	hasHeaderWindow := t.hasHeaderWindow()