diff --git a/intern/cycles/blender/addon/properties.py b/intern/cycles/blender/addon/properties.py
index 37323b2fd33..9bd1db2ea99 100644
--- a/intern/cycles/blender/addon/properties.py
+++ b/intern/cycles/blender/addon/properties.py
@@ -374,6 +374,7 @@ def update_pause(self, context):
 
 
 class CyclesRenderSettings(bpy.types.PropertyGroup):
+    __slots__ = ()
 
     device: EnumProperty(
         name="Device",
@@ -1111,6 +1112,7 @@ class CyclesRenderSettings(bpy.types.PropertyGroup):
 
 
 class CyclesCustomCameraSettings(bpy.types.PropertyGroup):
+    __slots__ = ()
 
     @classmethod
     def register(cls):
@@ -1126,6 +1128,7 @@ class CyclesCustomCameraSettings(bpy.types.PropertyGroup):
 
 
 class CyclesMaterialSettings(bpy.types.PropertyGroup):
+    __slots__ = ()
 
     emission_sampling: EnumProperty(
         name="Emission Sampling",
@@ -1182,6 +1185,7 @@ class CyclesMaterialSettings(bpy.types.PropertyGroup):
 
 
 class CyclesLightSettings(bpy.types.PropertyGroup):
+    __slots__ = ()
 
     max_bounces: IntProperty(
         name="Max Bounces",
@@ -1222,6 +1226,7 @@ class CyclesLightSettings(bpy.types.PropertyGroup):
 
 
 class CyclesWorldSettings(bpy.types.PropertyGroup):
+    __slots__ = ()
 
     is_caustics_light: BoolProperty(
         name="Shadow Caustics",
@@ -1288,6 +1293,7 @@ class CyclesWorldSettings(bpy.types.PropertyGroup):
 
 
 class CyclesVisibilitySettings(bpy.types.PropertyGroup):
+    __slots__ = ()
 
     camera: BoolProperty(
         name="Camera",
@@ -1340,6 +1346,8 @@ class CyclesVisibilitySettings(bpy.types.PropertyGroup):
 
 
 class CyclesMeshSettings(bpy.types.PropertyGroup):
+    __slots__ = ()
+
     @classmethod
     def register(cls):
         bpy.types.Mesh.cycles = PointerProperty(
@@ -1366,6 +1374,7 @@ class CyclesMeshSettings(bpy.types.PropertyGroup):
 
 
 class CyclesObjectSettings(bpy.types.PropertyGroup):
+    __slots__ = ()
 
     use_motion_blur: BoolProperty(
         name="Use Motion Blur",
@@ -1464,6 +1473,7 @@ class CyclesObjectSettings(bpy.types.PropertyGroup):
 
 
 class CyclesCurveRenderSettings(bpy.types.PropertyGroup):
+    __slots__ = ()
 
     shape: EnumProperty(
         name="Shape",
@@ -1492,6 +1502,7 @@ class CyclesCurveRenderSettings(bpy.types.PropertyGroup):
 
 
 class CyclesRenderLayerSettings(bpy.types.PropertyGroup):
+    __slots__ = ()
 
     pass_debug_sample_count: BoolProperty(
         name="Debug Sample Count",
@@ -1546,6 +1557,8 @@ class CyclesRenderLayerSettings(bpy.types.PropertyGroup):
 
 
 class CyclesDeviceSettings(bpy.types.PropertyGroup):
+    __slots__ = ()
+
     id: StringProperty(name="ID")
     name: StringProperty(name="Name")
     use: BoolProperty(name="Use", default=True)
@@ -1929,6 +1942,8 @@ class CyclesPreferences(bpy.types.AddonPreferences):
 
 
 class CyclesView3DShadingSettings(bpy.types.PropertyGroup):
+    __slots__ = ()
+
     render_pass: EnumProperty(
         name="Render Pass",
         description="Render pass to show in the 3D Viewport",
diff --git a/scripts/addons_core/bl_pkg/__init__.py b/scripts/addons_core/bl_pkg/__init__.py
index 48270406a96..b1c14bd7fe4 100644
--- a/scripts/addons_core/bl_pkg/__init__.py
+++ b/scripts/addons_core/bl_pkg/__init__.py
@@ -673,8 +673,7 @@ def cli_extension(argv):
 
 
 class BlExtDummyGroup(bpy.types.PropertyGroup):
-    # Dummy.
-    pass
+    __slots__ = ()
 
 
 # -----------------------------------------------------------------------------
diff --git a/scripts/addons_core/io_scene_gltf2/__init__.py b/scripts/addons_core/io_scene_gltf2/__init__.py
index 462c0788cb4..0c62f3cf5f0 100755
--- a/scripts/addons_core/io_scene_gltf2/__init__.py
+++ b/scripts/addons_core/io_scene_gltf2/__init__.py
@@ -2113,6 +2113,8 @@ def import_panel_user_extension(context, layout):
 
 
 class GLTF2_filter_action(bpy.types.PropertyGroup):
+    __slots__ = ()
+
     keep: bpy.props.BoolProperty(name="Keep Animation")
     action: bpy.props.PointerProperty(type=bpy.types.Action)
 
diff --git a/scripts/startup/bl_operators/bone_selection_sets.py b/scripts/startup/bl_operators/bone_selection_sets.py
index 3fbaaab7bf2..635cc930220 100644
--- a/scripts/startup/bl_operators/bone_selection_sets.py
+++ b/scripts/startup/bl_operators/bone_selection_sets.py
@@ -25,10 +25,14 @@ from bpy.props import (
 
 
 class SelectionEntry(PropertyGroup):
+    __slots__ = ()
+
     name: StringProperty(name="Bone Name", override={'LIBRARY_OVERRIDABLE'})
 
 
 class SelectionSet(PropertyGroup):
+    __slots__ = ()
+
     name: StringProperty(name="Set Name", override={'LIBRARY_OVERRIDABLE'})
     bone_ids: CollectionProperty(
         type=SelectionEntry,
diff --git a/scripts/startup/bl_operators/node.py b/scripts/startup/bl_operators/node.py
index def88e233da..515f9a326fd 100644
--- a/scripts/startup/bl_operators/node.py
+++ b/scripts/startup/bl_operators/node.py
@@ -29,6 +29,8 @@ from bpy.app.translations import (
 
 
 class NodeSetting(PropertyGroup):
+    __slots__ = ()
+
     value: StringProperty(
         name="Value",
         description="Python expression to be evaluated "
diff --git a/scripts/startup/bl_operators/wm.py b/scripts/startup/bl_operators/wm.py
index 4de27b32e9d..10d184bc8a5 100644
--- a/scripts/startup/bl_operators/wm.py
+++ b/scripts/startup/bl_operators/wm.py
@@ -2665,6 +2665,8 @@ class WM_OT_toolbar_prompt(Operator):
 
 
 class BatchRenameAction(bpy.types.PropertyGroup):
+    __slots__ = ()
+
     # category: StringProperty()
     type: EnumProperty(
         name="Operation",