diff --git a/setup.cfg b/setup.cfg
index 1ae7ee7d..4f8936a7 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -27,7 +27,7 @@ install_requires =
     aiida-core~=2.2,<3
     Jinja2~=3.0
     aiida-quantumespresso~=4.4.0
-    aiidalab-widgets-base~=2.1
+    aiidalab-widgets-base[optimade]~=2.2.0a0
     aiida-pseudo~=1.4
     filelock~=3.8
     importlib-resources~=5.2
diff --git a/src/aiidalab_qe/app/structure/__init__.py b/src/aiidalab_qe/app/structure/__init__.py
index 215c7479..2fa9b2aa 100644
--- a/src/aiidalab_qe/app/structure/__init__.py
+++ b/src/aiidalab_qe/app/structure/__init__.py
@@ -7,7 +7,7 @@
 
 import aiida
 import ipywidgets as ipw
-import traitlets
+import traitlets as tl
 from aiidalab_widgets_base import (
     BasicCellEditor,
     BasicStructureEditor,
@@ -37,8 +37,6 @@
     ("ETFA molecule", file_path / "examples" / "ETFA.xyz"),
 ]
 
-OptimadeQueryWidget.title = "OPTIMADE"  # monkeypatch
-
 
 class StructureSelectionStep(ipw.VBox, WizardAppWidgetStep):
     """Integrated widget for the selection and edition of structure.
@@ -47,8 +45,8 @@ class StructureSelectionStep(ipw.VBox, WizardAppWidgetStep):
     structure importers and the structure editors can be extended by plugins.
     """
 
-    structure = traitlets.Instance(aiida.orm.StructureData, allow_none=True)
-    confirmed_structure = traitlets.Instance(aiida.orm.StructureData, allow_none=True)
+    structure = tl.Instance(aiida.orm.StructureData, allow_none=True)
+    confirmed_structure = tl.Instance(aiida.orm.StructureData, allow_none=True)
 
     def __init__(self, description=None, **kwargs):
         importers = [
@@ -121,7 +119,7 @@ def __init__(self, description=None, **kwargs):
             **kwargs,
         )
 
-    @traitlets.default("state")
+    @tl.default("state")
     def _default_state(self):
         return self.State.INIT
 
@@ -137,7 +135,7 @@ def _update_state(self):
             else:
                 self.state = self.State.SUCCESS
 
-    @traitlets.observe("structure")
+    @tl.observe("structure")
     def _observe_structure(self, change):
         structure = change["new"]
         with self.hold_trait_notifications():
@@ -148,12 +146,12 @@ def _observe_structure(self, change):
                 self.structure_name_text.value = str(self.structure.get_formula())
             self._update_state()
 
-    @traitlets.observe("confirmed_structure")
+    @tl.observe("confirmed_structure")
     def _observe_confirmed_structure(self, _):
         with self.hold_trait_notifications():
             self._update_state()
 
-    @traitlets.observe("state")
+    @tl.observe("state")
     def _observe_state(self, change):
         with self.hold_trait_notifications():
             state = change["new"]