diff --git a/toolbar/hermes_bridge.shelf b/toolbar/hermes_bridge.shelf
index f57fedb..464f0f8 100644
--- a/toolbar/hermes_bridge.shelf
+++ b/toolbar/hermes_bridge.shelf
@@ -43,7 +43,7 @@ class HermesBridgeDialog(QtWidgets.QDialog):
     def _build_ui(self):
         self.setWindowTitle("Hermes Bridge")
         self.setMinimumWidth(420)
-        self.setWindowFlags(self.windowFlags() | QtCore.Qt.WindowStaysOnTopHint)
+        self.setAttribute(QtCore.Qt.WA_DeleteOnClose, False)
 
         # Dark theme
         self.setStyleSheet("""
@@ -162,9 +162,13 @@ class HermesBridgeDialog(QtWidgets.QDialog):
         QtCore.QTimer.singleShot(2000,
             lambda: self.btn_copy.setText("Copy"))
 
-# ── Show dialog ─────────────────────────────────────
-dialog = HermesBridgeDialog(hou.ui.mainQtWindow())
+# ── Show dialog (persist in hou.session per SideFX docs) ──
+if not hasattr(hou.session, "hermes_bridge_dialog") or hou.session.hermes_bridge_dialog is None:
+    hou.session.hermes_bridge_dialog = HermesBridgeDialog(hou.ui.mainQtWindow())
+dialog = hou.session.hermes_bridge_dialog
 dialog.show()
+dialog.raise_()
+dialog.activateWindow()
 ]]></script>
   </tool>
 </shelfDocument>