diff --git a/platform/xdebugger-impl/src/com/intellij/xdebugger/impl/ui/XDebuggerExpressionComboBox.java b/platform/xdebugger-impl/src/com/intellij/xdebugger/impl/ui/XDebuggerExpressionComboBox.java
index b7e36066108a..a055757c9814 100644
--- a/platform/xdebugger-impl/src/com/intellij/xdebugger/impl/ui/XDebuggerExpressionComboBox.java
+++ b/platform/xdebugger-impl/src/com/intellij/xdebugger/impl/ui/XDebuggerExpressionComboBox.java
@@ -1,6 +1,4 @@
-/*
- * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
- */
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.xdebugger.impl.ui;
 
 import com.intellij.openapi.editor.Document;
@@ -102,18 +100,12 @@ public class XDebuggerExpressionComboBox extends XDebuggerEditorBase {
   }
 
   private void fillComboBox() {
+    myModel.setSelectedItem(null); // must do this to preserve current editor
     myModel.replaceAll(getRecentExpressions());
-    if (myComboBox.getItemCount() > 0) {
-      myComboBox.setSelectedIndex(0);
-    }
   }
 
   @Override
   protected void doSetText(XExpression text) {
-    if (myComboBox.getItemCount() > 0) {
-      myComboBox.setSelectedIndex(0);
-    }
-
     //if (myComboBox.isEditable()) {
       myEditor.setItem(text);
     //}
@@ -189,11 +181,10 @@ public class XDebuggerExpressionComboBox extends XDebuggerEditorBase {
 
     @Override
     public void setItem(Object anObject) {
-      if (anObject == null) {
-        anObject = XExpressionImpl.EMPTY_EXPRESSION;
+      if (anObject != null) { // do not reset the editor on null
+        XExpression expression = (XExpression)anObject;
+        myDelegate.getEditorComponent().setNewDocumentAndFileType(getFileType(expression), createDocument(expression));
       }
-      XExpression expression = (XExpression)anObject;
-      myDelegate.getEditorComponent().setNewDocumentAndFileType(getFileType(expression), createDocument(expression));
     }
 
     @Override