diff --git a/.gitignore b/.gitignore
index 5d8904e..012e517 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,4 @@ build.sh
 subprojects/libhandy-*
 subprojects/packagecache
 *~
+.flatpak
diff --git a/com.github.bleakgrey.tootle.json b/com.github.bleakgrey.tootle.json
index 1628061..0f9ff2d 100644
--- a/com.github.bleakgrey.tootle.json
+++ b/com.github.bleakgrey.tootle.json
@@ -2,7 +2,7 @@
     "app-id" : "com.github.bleakgrey.tootle",
     "runtime" : "org.gnome.Platform",
     "sdk" : "org.gnome.Sdk",
-    "runtime-version" : "40",
+    "runtime-version" : "43",
     "command" : "com.github.bleakgrey.tootle",
     "finish-args" : [
         "--device=dri",
@@ -11,7 +11,6 @@
         "--socket=fallback-x11",
         "--socket=wayland",
         "--talk-name=org.gtk.vfs",
-        "--talk-name=org.gtk.vfs.*",
         "--filesystem=xdg-run/gvfsd"
     ],
     "cleanup" : [
diff --git a/data/ui/dialogs/list_editor.ui b/data/ui/dialogs/list_editor.ui
index 1038798..562239f 100644
--- a/data/ui/dialogs/list_editor.ui
+++ b/data/ui/dialogs/list_editor.ui
@@ -103,7 +103,7 @@
             <property name="revealed">0</property>
             <signal name="response" handler="infobar_response" swapped="no"/>
             <child internal-child="action_area">
-              <object class="GtkButtonBox">
+              <object class="GtkBox">
                 <property name="can_focus">False</property>
                 <property name="spacing">6</property>
                 <property name="layout_style">end</property>
diff --git a/data/ui/dialogs/main.ui b/data/ui/dialogs/main.ui
index 97b6210..6a6f4b5 100644
--- a/data/ui/dialogs/main.ui
+++ b/data/ui/dialogs/main.ui
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <interface>
-  <requires lib="gtk+" version="3.20"/>
-  <requires lib="libhandy" version="1.0"/>
+  <requires lib="gtk" version="4.0"/>
+  <requires lib="libadwaita" version="1.0"/>
   <template class="TootleDialogsMainWindow" parent="AdwApplicationWindow">
     <property name="width_request">360</property>
     <property name="height_request">600</property>
@@ -10,6 +10,9 @@
       <object class="AdwFlap" id="flap">
         <child type="flap">
           <object class="TootleViewsSidebar" id="sidebar">
+            <style>
+              <class name="background"/>
+            </style>
           </object>
         </child>
         <!-- <child type="separator"> -->
@@ -19,10 +22,9 @@
         <!-- </child> -->
         <child type="content">
           <object class="AdwLeaflet" id="leaflet">
-            <property name="can-swipe-back">1</property>
+            <property name="can-navigate-back">1</property>
             <property name="can-unfold">0</property>
-            <property name="hhomogeneous-folded">0</property>
-            <property name="hhomogeneous-unfolded">1</property>
+            <property name="homogeneous">1</property>
             <signal name="notify::child-transition-running" handler="on_child_transition"/>
             <signal name="notify::visible-child" handler="on_view_changed"/>
           </object>
diff --git a/data/ui/dialogs/new_account.ui b/data/ui/dialogs/new_account.ui
index f7c0a29..f5cfd3c 100644
--- a/data/ui/dialogs/new_account.ui
+++ b/data/ui/dialogs/new_account.ui
@@ -8,7 +8,7 @@
     <property name="title" translatable="yes">Add Account</property>
     <child>
       <object class="AdwLeaflet" id="deck">
-        <property name="can_swipe_back">1</property>
+        <property name="can_navigate_back">1</property>
         <property name="can_unfold">0</property>
         <signal name="notify::visible_child" handler="on_visible_child_notify" swapped="no"/>
         <child>
diff --git a/src/API/Attachment.vala b/src/API/Attachment.vala
index 88bc5bb..b45ac21 100644
--- a/src/API/Attachment.vala
+++ b/src/API/Attachment.vala
@@ -4,10 +4,9 @@ public class Tootle.API.Attachment : Entity, Widgetizable {
 	public string kind { get; set; default = "unknown"; }
 	public string url { get; set; }
 	public string? description { get; set; }
-	public string? _preview_url { get; set; }
 	public string? preview_url {
-		set { this._preview_url = value; }
-		get { return (this._preview_url == null || this._preview_url == "") ? url : _preview_url; }
+		set { this.preview_url = value; }
+		get { return (this.preview_url == null || this.preview_url == "") ? url : preview_url; }
 	}
 
 	public File? source_file { get; set; }
diff --git a/src/API/Mention.vala b/src/API/Mention.vala
index 73a4ee5..d981974 100644
--- a/src/API/Mention.vala
+++ b/src/API/Mention.vala
@@ -21,7 +21,7 @@ public class Tootle.API.Mention : Entity, Widgetizable {
     }
 
 	public override void open () {
-		Views.Profile.open_from_id (id);
+		Views.Profile.open_from_id (this.id);
 	}
 
 }
diff --git a/src/API/Status.vala b/src/API/Status.vala
index 4f92cdb..564e707 100644
--- a/src/API/Status.vala
+++ b/src/API/Status.vala
@@ -28,7 +28,7 @@ public class Tootle.API.Status : Entity, Widgetizable {
     public ArrayList<API.Mention>? mentions { get; set; default = null; }
     public ArrayList<API.Attachment>? media_attachments { get; set; default = null; }
 
-    public string? _url { get; set; }
+    private string? _url;
     public string url {
         owned get { return this.get_modified_url (); }
         set { this._url = value; }
diff --git a/src/Application.vala b/src/Application.vala
index 57d0fd7..b48cb53 100644
--- a/src/Application.vala
+++ b/src/Application.vala
@@ -43,7 +43,7 @@ namespace Tootle {
 			{ null }
 		};
 
-		public const GLib.ActionEntry[] app_entries = {
+		private const GLib.ActionEntry[] app_entries = {
 			{ "about", about_activated },
 			{ "compose", compose_activated },
 			{ "back", back_activated },
diff --git a/src/Dialogs/NewAccount.vala b/src/Dialogs/NewAccount.vala
index 4de74b9..1ef94fb 100644
--- a/src/Dialogs/NewAccount.vala
+++ b/src/Dialogs/NewAccount.vala
@@ -211,7 +211,7 @@ public class Tootle.Dialogs.NewAccount: Adw.Window {
 		if (!deck.child_transition_running && deck.visible_child == instance_step)
 			reset ();
 
-		deck.can_swipe_back = deck.visible_child != done_step;
+		deck.can_navigate_back = deck.visible_child != done_step;
 	}
 
 }
diff --git a/src/Services/Accounts/InstanceAccount.vala b/src/Services/Accounts/InstanceAccount.vala
index ab04dfa..3bafc98 100644
--- a/src/Services/Accounts/InstanceAccount.vala
+++ b/src/Services/Accounts/InstanceAccount.vala
@@ -177,7 +177,7 @@ public class Tootle.InstanceAccount : API.Account, Streamable {
 
 	// Streamable
 
-	public string? _connection_url { get; set; }
+	public string? connection_url { get; set; }
 	public bool subscribed { get; set; }
 
 	public virtual string? get_stream_url () {
diff --git a/src/Services/Network/Streamable.vala b/src/Services/Network/Streamable.vala
index 2dcabd0..9a76b7c 100644
--- a/src/Services/Network/Streamable.vala
+++ b/src/Services/Network/Streamable.vala
@@ -20,7 +20,7 @@ public abstract interface Tootle.Streamable : Object {
 		}
 	}
 
-	public abstract string? _connection_url { get; set; }
+	private abstract string? connection_url { get; set; }
 	public abstract bool subscribed { get; set; default = false; }
 
     public abstract string? get_stream_url ();
@@ -29,14 +29,14 @@ public abstract interface Tootle.Streamable : Object {
     public signal void stream_event (Event ev);
 
 	void subscribe () {
-		streams.unsubscribe (_connection_url, this);
+		streams.unsubscribe (connection_url, this);
 		streams.subscribe (get_stream_url (), this);
-		_connection_url = get_stream_url ();
+		connection_url = get_stream_url ();
 	}
 
 	void unsubscribe () {
 		streams.unsubscribe (get_stream_url (), this);
-		_connection_url = null;
+		connection_url = null;
 	}
 
 	public string get_subscriber_name () {
diff --git a/src/Views/Base.vala b/src/Views/Base.vala
index a990b1f..9d823bf 100644
--- a/src/Views/Base.vala
+++ b/src/Views/Base.vala
@@ -61,7 +61,7 @@ public class Tootle.Views.Base : Box {
     protected virtual void build_actions () {}
 
 	protected virtual void build_header () {
-		var title = new Adw.WindowTitle (null, null);
+		var title = new Adw.WindowTitle ("Tootle", "");
 		bind_property ("label", title, "title", BindingFlags.SYNC_CREATE);
 		header.title_widget = title;
 	}
diff --git a/src/Views/Timeline.vala b/src/Views/Timeline.vala
index 27d79d7..183b5ee 100644
--- a/src/Views/Timeline.vala
+++ b/src/Views/Timeline.vala
@@ -132,7 +132,7 @@ public class Tootle.Views.Timeline : AccountHolder, Streamable, Views.ContentBas
 
 	// Streamable
 
-	public string? _connection_url { get; set; }
+	public string? connection_url { get; set; }
 	public bool subscribed { get; set; }
 
 	protected override void on_streaming_policy_changed () {