diff --git a/blender_cloud/attract/__init__.py b/blender_cloud/attract/__init__.py
index 3b15361..26bca74 100644
--- a/blender_cloud/attract/__init__.py
+++ b/blender_cloud/attract/__init__.py
@@ -955,6 +955,9 @@ def deactivate():
             pass
 
 
+_rna_classes = [cls for cls in locals() if isinstance(cls, type) and hasattr(cls, 'bl_rna')]
+
+
 def register():
     bpy.types.Sequence.atc_is_synced = bpy.props.BoolProperty(name="Is Synced")
     bpy.types.Sequence.atc_object_id = bpy.props.StringProperty(name="Attract Object ID")
@@ -980,22 +983,18 @@ def register():
 
     bpy.types.SEQUENCER_PT_edit.append(draw_strip_movie_meta)
 
-    bpy.utils.register_class(AttractToolsPanel)
-    bpy.utils.register_class(AttractShotRelink)
-    bpy.utils.register_class(AttractShotDelete)
-    bpy.utils.register_class(AttractStripUnlink)
-    bpy.utils.register_class(AttractShotFetchUpdate)
-    bpy.utils.register_class(AttractShotSubmitSelected)
-    bpy.utils.register_class(ATTRACT_OT_submit_all)
-    bpy.utils.register_class(ATTRACT_OT_open_meta_blendfile)
-    bpy.utils.register_class(ATTRACT_OT_shot_open_in_browser)
-    bpy.utils.register_class(ATTRACT_OT_make_shot_thumbnail)
-    bpy.utils.register_class(ATTRACT_OT_copy_id_to_clipboard)
+    for cls in _rna_classes:
+        bpy.utils.register_class(cls)
 
 
 def unregister():
     deactivate()
-    bpy.utils.unregister_module(__name__)
+    for cls in _rna_classes:
+        try:
+            bpy.utils.unregister_class(cls)
+        except RuntimeError:
+            log.warning('Unable to unregister class %r, probably already unregistered', cls)
+
     del bpy.types.Sequence.atc_is_synced
     del bpy.types.Sequence.atc_object_id
     del bpy.types.Sequence.atc_object_id_conflict
diff --git a/blender_cloud/flamenco/__init__.py b/blender_cloud/flamenco/__init__.py
index c840b30..4882702 100644
--- a/blender_cloud/flamenco/__init__.py
+++ b/blender_cloud/flamenco/__init__.py
@@ -814,19 +814,19 @@ def flamenco_do_override_output_path_updated(scene, context):
     log.info('Setting Override Output Path to %s', scene.flamenco_override_output_path)
 
 
+# FlamencoManagerGroup needs to be registered before classes that use it.
+_rna_classes = [FlamencoManagerGroup]
+_rna_classes.extend(
+    cls for cls in locals()
+    if isinstance(cls, type) and hasattr(cls, 'bl_rna') and cls not in _rna_classes
+)
+
+
 def register():
     from ..utils import redraw
 
-    bpy.utils.register_class(FlamencoManagerGroup)
-    bpy.utils.register_class(FLAMENCO_OT_fmanagers)
-    bpy.utils.register_class(FLAMENCO_OT_render)
-    bpy.utils.register_class(FLAMENCO_OT_scene_to_frame_range)
-    bpy.utils.register_class(FLAMENCO_OT_copy_files)
-    bpy.utils.register_class(FLAMENCO_OT_explore_file_path)
-    bpy.utils.register_class(FLAMENCO_OT_enable_output_path_override)
-    bpy.utils.register_class(FLAMENCO_OT_disable_output_path_override)
-    bpy.utils.register_class(FLAMENCO_OT_abort)
-    bpy.utils.register_class(FLAMENCO_PT_render)
+    for cls in _rna_classes:
+        bpy.utils.register_class(cls)
 
     scene = bpy.types.Scene
     scene.flamenco_render_fchunk_size = IntProperty(
@@ -917,7 +917,11 @@ def register():
 
 def unregister():
     deactivate()
-    bpy.utils.unregister_module(__name__)
+    for cls in _rna_classes:
+        try:
+            bpy.utils.unregister_class(cls)
+        except RuntimeError:
+            log.warning('Unable to unregister class %r, probably already unregistered', cls)
 
     for name in ('flamenco_render_fchunk_size',
                  'flamenco_render_schunk_count',
diff --git a/blender_cloud/image_sharing.py b/blender_cloud/image_sharing.py
index 779ff1e..b64cdd4 100644
--- a/blender_cloud/image_sharing.py
+++ b/blender_cloud/image_sharing.py
@@ -323,20 +323,25 @@ def window_menu(self, context):
     props.screenshot_full = True
 
 
-def register():
-    bpy.utils.register_class(PILLAR_OT_image_share)
-
-    bpy.types.IMAGE_MT_image.append(image_editor_menu)
+def get_topbar_menu():
+    """Return the topbar menu in a Blender 2.79 and 2.80 compatible way."""
     try:
         menu = bpy.types.TOPBAR_MT_window
     except AttributeError:
         # Blender < 2.80
         menu = bpy.types.INFO_MT_window
-    menu.append(window_menu)
+    return menu
+
+
+def register():
+    bpy.utils.register_class(PILLAR_OT_image_share)
+
+    bpy.types.IMAGE_MT_image.append(image_editor_menu)
+    get_topbar_menu().append(window_menu)
 
 
 def unregister():
     bpy.utils.unregister_class(PILLAR_OT_image_share)
 
     bpy.types.IMAGE_MT_image.remove(image_editor_menu)
-    bpy.types.INFO_MT_window.remove(window_menu)
+    get_topbar_menu().remove(window_menu)