diff --git a/platform/editor-ui-api/src/com/intellij/ide/util/treeView/NodeDescriptor.java b/platform/editor-ui-api/src/com/intellij/ide/util/treeView/NodeDescriptor.java
index 3494752647ae..2f67972d00db 100644
--- a/platform/editor-ui-api/src/com/intellij/ide/util/treeView/NodeDescriptor.java
+++ b/platform/editor-ui-api/src/com/intellij/ide/util/treeView/NodeDescriptor.java
@@ -66,7 +66,10 @@ public abstract class NodeDescriptor<E> {
   public abstract E getElement();
 
   public String toString() {
-    return String.valueOf(myName);
+    // NB!: this method may return null if node is not valid
+    // it contradicts the specification, but the fix breaks existing behaviour
+    // see com.intellij.ide.util.FileStructurePopup#getSpeedSearchText
+    return myName;
   }
 
   /**
diff --git a/platform/lang-impl/src/com/intellij/ide/util/FileStructurePopup.java b/platform/lang-impl/src/com/intellij/ide/util/FileStructurePopup.java
index 417d3685244a..eb7e60f7deee 100644
--- a/platform/lang-impl/src/com/intellij/ide/util/FileStructurePopup.java
+++ b/platform/lang-impl/src/com/intellij/ide/util/FileStructurePopup.java
@@ -996,7 +996,8 @@ public class FileStructurePopup implements Disposable, TreeActionsOwner {
       }
       return text;
     }
-
+    // NB!: this point is achievable if the following method returns null
+    // see com.intellij.ide.util.treeView.NodeDescriptor.toString
     if (userObject instanceof StructureViewComponent.StructureViewTreeElementWrapper) {
       return ApplicationManager.getApplication().runReadAction(new Computable<String>() {
         @Nullable