diff --git a/platform/platform-impl/src/com/intellij/openapi/wm/impl/status/ToolWindowsWidget.java b/platform/platform-impl/src/com/intellij/openapi/wm/impl/status/ToolWindowsWidget.java
index 4609acf0fd4b..dac743069bd0 100644
--- a/platform/platform-impl/src/com/intellij/openapi/wm/impl/status/ToolWindowsWidget.java
+++ b/platform/platform-impl/src/com/intellij/openapi/wm/impl/status/ToolWindowsWidget.java
@@ -59,7 +59,7 @@ class ToolWindowsWidget extends JLabel implements CustomStatusBarWidget, StatusB
   private JBPopup popup;
   private boolean wasExited = false;
 
-  ToolWindowsWidget(Disposable parent) {
+  ToolWindowsWidget(@NotNull Disposable parent) {
     new BaseButtonBehavior(this, TimedDeadzone.NULL) {
       @Override
       protected void execute(MouseEvent e) {