diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/NotSignedInDialog.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/NotSignedInDialog.java
index af86a21501..f3544964fe 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/NotSignedInDialog.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/NotSignedInDialog.java
@@ -16,26 +16,35 @@ package com.google.gerrit.client;
 
 import com.google.gwt.event.dom.client.ClickEvent;
 import com.google.gwt.event.dom.client.ClickHandler;
+import com.google.gwt.event.logical.shared.CloseEvent;
+import com.google.gwt.event.logical.shared.CloseHandler;
 import com.google.gwt.user.client.DOM;
 import com.google.gwt.user.client.History;
 import com.google.gwt.user.client.ui.Button;
 import com.google.gwt.user.client.ui.FlowPanel;
 import com.google.gwt.user.client.ui.HTML;
+import com.google.gwt.user.client.ui.PopupPanel;
+import com.google.gwtexpui.globalkey.client.GlobalKey;
 import com.google.gwtexpui.user.client.AutoCenterDialogBox;
 
 /** A dialog box telling the user they are not signed in. */
-public class NotSignedInDialog extends AutoCenterDialogBox {
+public class NotSignedInDialog extends AutoCenterDialogBox implements CloseHandler<PopupPanel> {
+
+  private Button signin;
+  private boolean buttonClicked = false;
+
   public NotSignedInDialog() {
     super(/* auto hide */false, /* modal */true);
     setGlassEnabled(true);
     setText(Gerrit.C.notSignedInTitle());
 
     final FlowPanel buttons = new FlowPanel();
-    final Button signin = new Button();
+    signin = new Button();
     signin.setText(Gerrit.C.menuSignIn());
     signin.addClickHandler(new ClickHandler() {
       @Override
       public void onClick(ClickEvent event) {
+        buttonClicked = true;
         hide();
         Gerrit.doSignIn(History.getToken());
       }
@@ -48,6 +57,7 @@ public class NotSignedInDialog extends AutoCenterDialogBox {
     close.addClickHandler(new ClickHandler() {
       @Override
       public void onClick(ClickEvent event) {
+        buttonClicked = true;
         Gerrit.deleteSessionCookie();
         hide();
       }
@@ -60,5 +70,23 @@ public class NotSignedInDialog extends AutoCenterDialogBox {
     add(center);
 
     center.setWidth("400px");
+
+    addCloseHandler(this);
+  }
+
+  @Override
+  public void onClose(CloseEvent<PopupPanel> event) {
+    if (!buttonClicked) {
+      // the dialog was closed without one of the buttons being pressed
+      // e.g. the user pressed ESC to close the dialog
+      Gerrit.deleteSessionCookie();
+    }
+  }
+
+  @Override
+  public void center() {
+    super.center();
+    GlobalKey.dialog(this);
+    signin.setFocus(true);
   }
 }