diff --git a/libdino/src/service/avatar_manager.vala b/libdino/src/service/avatar_manager.vala
index 1296856b..3bd38e72 100644
--- a/libdino/src/service/avatar_manager.vala
+++ b/libdino/src/service/avatar_manager.vala
@@ -52,7 +52,7 @@ public class AvatarManager : StreamInteractionModule, Object {
         if (hash == null) return null;
         File file = File.new_for_path(Path.build_filename(folder, hash));
         if (!file.query_exists()) {
-            fetch_and_store_for_jid(account, jid_);
+            fetch_and_store_for_jid.begin(account, jid_);
             return null;
         } else {
             return file;
@@ -169,7 +169,7 @@ public class AvatarManager : StreamInteractionModule, Object {
         );
 
         foreach (var entry in get_avatar_hashes(account, Source.USER_AVATARS).entries) {
-            on_user_avatar_received(account, entry.key, entry.value);
+            on_user_avatar_received.begin(account, entry.key, entry.value);
         }
         foreach (var entry in get_avatar_hashes(account, Source.VCARD).entries) {
 
@@ -179,7 +179,7 @@ public class AvatarManager : StreamInteractionModule, Object {
                 continue;
             }
 
-            on_vcard_avatar_received(account, entry.key, entry.value);
+            on_vcard_avatar_received.begin(account, entry.key, entry.value);
         }
     }
 
diff --git a/libdino/src/service/history_sync.vala b/libdino/src/service/history_sync.vala
index 0c0571bb..8ab6d7bb 100644
--- a/libdino/src/service/history_sync.vala
+++ b/libdino/src/service/history_sync.vala
@@ -388,9 +388,6 @@ public class Dino.HistorySync {
             page_result = PageResult.NoMoreMessages;
         }
 
-        string selection = null;
-        string[] selection_args = {};
-
         string query_id = query_params.query_id;
         string? after_id = query_params.start_id;
 
diff --git a/libdino/src/service/message_processor.vala b/libdino/src/service/message_processor.vala
index 01687083..baab37ce 100644
--- a/libdino/src/service/message_processor.vala
+++ b/libdino/src/service/message_processor.vala
@@ -167,7 +167,6 @@ public class MessageProcessor : StreamInteractionModule, Object {
         new_message.counterpart = counterpart_override ?? (new_message.direction == Entities.Message.DIRECTION_SENT ? message.to : message.from);
         new_message.ourpart = new_message.direction == Entities.Message.DIRECTION_SENT ? message.from : message.to;
 
-        XmppStream? stream = stream_interactor.get_stream(account);
         Xmpp.MessageArchiveManagement.MessageFlag? mam_message_flag = Xmpp.MessageArchiveManagement.MessageFlag.get_flag(message);
         EntityInfo entity_info = stream_interactor.get_module(EntityInfo.IDENTITY);
         if (mam_message_flag != null && mam_message_flag.mam_id != null) {
diff --git a/main/src/ui/call_window/call_window.vala b/main/src/ui/call_window/call_window.vala
index 14b67449..08ea4b21 100644
--- a/main/src/ui/call_window/call_window.vala
+++ b/main/src/ui/call_window/call_window.vala
@@ -253,11 +253,12 @@ namespace Dino.Ui {
         }
 
         private bool on_get_child_position(Widget widget, out Gdk.Rectangle allocation) {
+            allocation = Gdk.Rectangle();
+
             if (widget == own_video_box) {
                 int width = get_size(Orientation.HORIZONTAL);
                 int height = get_size(Orientation.VERTICAL);
 
-                allocation = Gdk.Rectangle();
                 allocation.width = own_video_width;
                 allocation.height = own_video_height;
                 allocation.x = width - own_video_width - 20;
diff --git a/main/src/ui/conversation_content_view/conversation_view.vala b/main/src/ui/conversation_content_view/conversation_view.vala
index 4006a02f..33cb3b22 100644
--- a/main/src/ui/conversation_content_view/conversation_view.vala
+++ b/main/src/ui/conversation_content_view/conversation_view.vala
@@ -329,7 +329,7 @@ public class ConversationView : Widget, Plugins.ConversationItemCollection, Plug
             do_insert_item(item);
         }
         ContentMetaItem meta_item = content_populator.get_content_meta_item(content_item);
-        Widget w = insert_new(meta_item);
+        insert_new(meta_item);
         content_items.add(meta_item);
         meta_items.add(meta_item);
 
diff --git a/main/src/ui/conversation_content_view/file_image_widget.vala b/main/src/ui/conversation_content_view/file_image_widget.vala
index 43c3b74d..a3579185 100644
--- a/main/src/ui/conversation_content_view/file_image_widget.vala
+++ b/main/src/ui/conversation_content_view/file_image_widget.vala
@@ -45,7 +45,6 @@ public class FileImageWidget : Box {
         image.add_controller(gesture_click_controller);
 
         FileInfo file_info = file.query_info("*", FileQueryInfoFlags.NONE);
-        string? mime_type = file_info.get_content_type();
 
         MenuButton button = new MenuButton();
         button.icon_name = "view-more";
diff --git a/main/src/ui/conversation_details.vala b/main/src/ui/conversation_details.vala
index 70c8ce6d..82d6ae54 100644
--- a/main/src/ui/conversation_details.vala
+++ b/main/src/ui/conversation_details.vala
@@ -26,15 +26,18 @@ namespace Dino.Ui.ConversationDetails {
         model.display_name.bind_property("display-name", view_model, "name", BindingFlags.SYNC_CREATE);
         model.conversation.bind_property("notify-setting", view_model, "notification", BindingFlags.SYNC_CREATE, (_, from, ref to) => {
             switch (model.conversation.get_notification_setting(stream_interactor)) {
-                case Conversation.NotifySetting.ON:
+                case ON:
                     to = ViewModel.ConversationDetails.NotificationSetting.ON;
                     break;
-                case Conversation.NotifySetting.OFF:
+                case OFF:
                     to = ViewModel.ConversationDetails.NotificationSetting.OFF;
                     break;
-                case Conversation.NotifySetting.HIGHLIGHT:
+                case HIGHLIGHT:
                     to = ViewModel.ConversationDetails.NotificationSetting.HIGHLIGHT;
                     break;
+                case DEFAULT:
+                    // A "default" setting should have been resolved to the actual default value
+                    assert_not_reached();
             }
             return true;
         });
diff --git a/main/src/ui/conversation_selector/conversation_selector.vala b/main/src/ui/conversation_selector/conversation_selector.vala
index 535a61b0..d16ef3ee 100644
--- a/main/src/ui/conversation_selector/conversation_selector.vala
+++ b/main/src/ui/conversation_selector/conversation_selector.vala
@@ -14,7 +14,6 @@ public class ConversationSelector : Widget {
     ListBox list_box = new ListBox() { hexpand=true };
 
     private StreamInteractor stream_interactor;
-    private uint? drag_timeout;
     private HashMap<Conversation, ConversationSelectorRow> rows = new HashMap<Conversation, ConversationSelectorRow>(Conversation.hash_func, Conversation.equals_func);
 
     public ConversationSelector init(StreamInteractor stream_interactor) {
diff --git a/main/src/ui/notifier_gnotifications.vala b/main/src/ui/notifier_gnotifications.vala
index 90c8ca8c..4d36620d 100644
--- a/main/src/ui/notifier_gnotifications.vala
+++ b/main/src/ui/notifier_gnotifications.vala
@@ -109,6 +109,8 @@ namespace Dino.Ui {
                 case ConnectionManager.ConnectionError.Source.TLS:
                     notification.set_body("Invalid TLS certificate");
                     break;
+                default:
+                    break;
             }
             GLib.Application.get_default().send_notification(account.id.to_string() + "-connection-error", notification);
         }
diff --git a/main/src/ui/occupant_menu/list.vala b/main/src/ui/occupant_menu/list.vala
index b9a4a74f..ce5a1981 100644
--- a/main/src/ui/occupant_menu/list.vala
+++ b/main/src/ui/occupant_menu/list.vala
@@ -153,7 +153,6 @@ public class List : Box {
         if (affiliation1 < affiliation2) return -1;
         else if (affiliation1 > affiliation2) return 1;
         else return row_wrapper1.name_label.label.collate(row_wrapper2.name_label.label);
-        return 0;
     }
 
     private int get_affiliation_ranking(Xmpp.Xep.Muc.Affiliation affiliation) {
diff --git a/main/src/ui/util/data_forms.vala b/main/src/ui/util/data_forms.vala
index d10196ab..39dce3ee 100644
--- a/main/src/ui/util/data_forms.vala
+++ b/main/src/ui/util/data_forms.vala
@@ -75,7 +75,6 @@ public static ViewModel.PreferencesRow.Any? get_data_form_field_view_model(DataF
                 if (option.value == list_single_field.value) combobox_model.active_item = i;
             }
             combobox_model.bind_property("active-item", list_single_field, "value", BindingFlags.DEFAULT, (binding, from, ref to) => {
-                var src_field = (DataForms.DataForm.ListSingleField) binding.dup_target();
                 var active_item = (int) from;
                 to = list_single_field.options[active_item].value;
                 return true;
diff --git a/main/src/ui/util/label_hybrid.vala b/main/src/ui/util/label_hybrid.vala
index f426de7e..0059d2ae 100644
--- a/main/src/ui/util/label_hybrid.vala
+++ b/main/src/ui/util/label_hybrid.vala
@@ -97,10 +97,6 @@ public class EntryLabelHybrid : LabelHybrid {
         }
     }
 
-    private void on_focus_leave() {
-        show_label();
-    }
-
     private void update_label() {
         if (visibility) {
             label.label = entry.text;
diff --git a/plugins/rtp/src/video_widget.vala b/plugins/rtp/src/video_widget.vala
index f69a2ba7..05cc5a6c 100644
--- a/plugins/rtp/src/video_widget.vala
+++ b/plugins/rtp/src/video_widget.vala
@@ -16,7 +16,7 @@ public class Dino.Plugins.Rtp.Paintable : Gdk.Paintable, Object {
 
     public override Gdk.Paintable get_current_image() {
         if (image != null) return image;
-        return Gdk.Paintable.new_empty(0, 0);
+        return Gdk.Paintable.empty(0, 0);
     }
 
     public override int get_intrinsic_width() {
diff --git a/xmpp-vala/src/core/xmpp_stream.vala b/xmpp-vala/src/core/xmpp_stream.vala
index 42e90bf9..54433b67 100644
--- a/xmpp-vala/src/core/xmpp_stream.vala
+++ b/xmpp-vala/src/core/xmpp_stream.vala
@@ -30,9 +30,9 @@ public abstract class Xmpp.XmppStream : Object {
         this.remote_name = remote_name;
     }
 
-    public abstract async void connect() throws IOError;
+    public abstract new async void connect() throws IOError;
 
-    public abstract async void disconnect() throws IOError;
+    public abstract new async void disconnect() throws IOError;
 
     public abstract async StanzaNode read() throws IOError;
 
diff --git a/xmpp-vala/src/module/xep/0082_date_time_profiles.vala b/xmpp-vala/src/module/xep/0082_date_time_profiles.vala
index 32d4d3ac..8b40d3ac 100644
--- a/xmpp-vala/src/module/xep/0082_date_time_profiles.vala
+++ b/xmpp-vala/src/module/xep/0082_date_time_profiles.vala
@@ -1,23 +1,11 @@
 namespace Xmpp.Xep.DateTimeProfiles {
 
 public DateTime? parse_string(string time_string) {
-    // TODO with glib >= 2.56
-    // return new DateTime.from_iso8601(time_string, null);
-
-    TimeVal time_val = TimeVal();
-    if (time_val.from_iso8601(time_string)) {
-        return new DateTime.from_unix_utc(time_val.tv_sec);
-    }
-    return null;
-
+     return new DateTime.from_iso8601(time_string, null);
 }
 
-
 public string to_datetime(DateTime time) {
-    // TODO with glib >= 2.62
-    // return time.to_utc().format_iso8601().to_string();
-
-    return time.to_utc().format("%Y-%m-%dT%H:%M:%SZ");
+     return time.to_utc().format_iso8601().to_string();
 }
 
 }