diff --git a/src/Application.vala b/src/Application.vala
index afbf15e31..a8744594d 100644
--- a/src/Application.vala
+++ b/src/Application.vala
@@ -155,13 +155,13 @@ namespace Scratch {
             if (active_window == null) {
                 if (location_jump_manager.has_selection_range () && location_jump_manager.has_override_target ()) {
                     RestoreOverride restore_override = location_jump_manager.create_restore_override ();
-                    add_window (new MainWindow.with_restore_override (true, restore_override));
+                    add_window (new MainWindow.primary_with_restore_override (restore_override));
                 } else {
-                    add_window (new MainWindow (true)); // Will restore documents if required
+                    add_window (new MainWindow.primary ()); // Will restore documents if required
                 }
             } else if (create_new_window) {
                 create_new_window = false;
-                add_window (new MainWindow (false)); // Will NOT restore documents in additional windows
+                add_window (new MainWindow.secondary ()); // Will NOT restore documents in additional windows
             }
 
             active_window.present ();
diff --git a/src/FolderManager/FileView.vala b/src/FolderManager/FileView.vala
index 2bb5035b3..712831390 100644
--- a/src/FolderManager/FileView.vala
+++ b/src/FolderManager/FileView.vala
@@ -38,23 +38,29 @@ public class Scratch.FolderManager.FileView : Code.Widgets.SourceList, Code.Pane
     public const string ACTION_CLOSE_OTHER_FOLDERS = "close-other-folders";
     public const string ACTION_SET_ACTIVE_PROJECT = "set-active-project";
 
+    private const ActionEntry[] PRIMARY_ONLY_ACTION_ENTRIES = {
+        { ACTION_SET_ACTIVE_PROJECT, action_set_active_project, "s"},
+        { ACTION_RENAME_FILE, action_rename_file, "s" },
+        { ACTION_RENAME_FOLDER, action_rename_folder, "s" }
+    };
+
     private const ActionEntry[] ACTION_ENTRIES = {
         { ACTION_LAUNCH_APP_WITH_FILE_PATH, action_launch_app_with_file_path, "as" },
         { ACTION_SHOW_APP_CHOOSER, action_show_app_chooser, "s" },
         { ACTION_EXECUTE_CONTRACT_WITH_FILE_PATH, action_execute_contract_with_file_path, "as" },
-        { ACTION_RENAME_FILE, action_rename_file, "s" },
-        { ACTION_RENAME_FOLDER, action_rename_folder, "s" },
         { ACTION_DELETE, action_delete, "s" },
         { ACTION_NEW_FILE, add_new_file, "s" },
         { ACTION_NEW_FOLDER, add_new_folder, "s"},
         { ACTION_CLOSE_FOLDER, action_close_folder, "s"},
-        { ACTION_CLOSE_OTHER_FOLDERS, action_close_other_folders, "s"},
-        { ACTION_SET_ACTIVE_PROJECT, action_set_active_project, "s"}
+        { ACTION_CLOSE_OTHER_FOLDERS, action_close_other_folders, "s"}
     };
 
     private GLib.Settings settings;
     private Scratch.Services.GitManager git_manager;
-    private Scratch.Services.PluginsManager plugins;
+    private unowned Scratch.MainWindow window;
+
+    public Scratch.Services.PluginsManager plugins { get; construct; }
+    public bool is_primary { get; construct; }
 
     public new signal void activate (string file);
     public signal bool rename_request (File file);
@@ -64,8 +70,12 @@ public class Scratch.FolderManager.FileView : Code.Widgets.SourceList, Code.Pane
     public string icon_name { get; set; }
     public string title { get; set; }
 
-    public FileView (Scratch.Services.PluginsManager plugins_manager) {
-        plugins = plugins_manager;
+    public FileView (Scratch.Services.PluginsManager plugins_manager, bool is_primary) {
+        Object (
+            root: new ExpandableItem (), //This does not get created by base class when chaining up
+            plugins: plugins_manager,
+            is_primary: is_primary
+        );
     }
 
     construct {
@@ -79,12 +89,22 @@ public class Scratch.FolderManager.FileView : Code.Widgets.SourceList, Code.Pane
 
         actions = new SimpleActionGroup ();
         actions.add_action_entries (ACTION_ENTRIES, this);
+        if (is_primary) {
+            actions.add_action_entries (PRIMARY_ONLY_ACTION_ENTRIES, this);
+        }
+
         insert_action_group (ACTION_GROUP, actions);
 
         realize.connect (() => {
             toplevel_action_group = get_action_group (MainWindow.ACTION_GROUP);
             assert_nonnull (toplevel_action_group);
         });
+
+        show_all ();
+
+        realize.connect (() => {
+            window = (Scratch.MainWindow) (this.get_toplevel ());
+        });
     }
 
     private void action_close_folder (SimpleAction action, GLib.Variant? parameter) {
@@ -122,7 +142,7 @@ public class Scratch.FolderManager.FileView : Code.Widgets.SourceList, Code.Pane
         }
 
         //Make remaining project the active one
-        git_manager.active_project_path = path;
+        window.active_project_path = path;  //Temporary fix
 
         write_settings ();
     }
@@ -138,7 +158,7 @@ public class Scratch.FolderManager.FileView : Code.Widgets.SourceList, Code.Pane
             return;
         }
 
-        git_manager.active_project_path = path;
+        window.active_project_path = path;
 
         write_settings ();
     }
@@ -195,7 +215,7 @@ public class Scratch.FolderManager.FileView : Code.Widgets.SourceList, Code.Pane
 
     public void collapse_other_projects () {
         unowned string path;
-        path = git_manager.active_project_path;
+        path = window.active_project_path;
 
         foreach (var child in root.children) {
             var project_folder = ((ProjectFolderItem) child);
@@ -592,10 +612,13 @@ public class Scratch.FolderManager.FileView : Code.Widgets.SourceList, Code.Pane
         yield;
     }
 
-    private bool is_open (File folder) {
-        foreach (var child in root.children)
-            if (folder.path == ((Item) child).path)
+    private bool is_open (File folder) requires (root != null) {
+        foreach (var child in root.children) {
+            if (folder.path == ((Item) child).path) {
                 return true;
+            }
+        }
+
         return false;
     }
 
diff --git a/src/FolderManager/FolderItem.vala b/src/FolderManager/FolderItem.vala
index 3f55c77c2..8aab7d590 100644
--- a/src/FolderManager/FolderItem.vala
+++ b/src/FolderManager/FolderItem.vala
@@ -116,7 +116,7 @@ namespace Scratch.FolderManager {
             } else {
                 var root = get_root_folder ();
                 if (root != null &&
-                    root.monitored_repo != null) {
+                    root.has_monitored_repo) {
                     //When toggled closed, update status to reflect hidden contents
                     root.update_item_status (this);
                 }
diff --git a/src/FolderManager/Item.vala b/src/FolderManager/Item.vala
index 19cb84f11..5a1ad924c 100644
--- a/src/FolderManager/Item.vala
+++ b/src/FolderManager/Item.vala
@@ -51,6 +51,10 @@ namespace Scratch.FolderManager {
             file.rename (new_name);
         }
 
+        public bool equal (Item b) {
+            return path == b.path;
+        }
+
         public void trash () {
             file.trash ();
         }
diff --git a/src/FolderManager/ProjectFolderItem.vala b/src/FolderManager/ProjectFolderItem.vala
index c53be4d55..673dd72fc 100644
--- a/src/FolderManager/ProjectFolderItem.vala
+++ b/src/FolderManager/ProjectFolderItem.vala
@@ -31,7 +31,13 @@ namespace Scratch.FolderManager {
 
         public signal void closed ();
 
-        public Scratch.Services.MonitoredRepository? monitored_repo { get; private set; default = null; }
+        // public Scratch.Services.MonitoredRepository? monitored_repo { get; private set; default = null; }
+        private Scratch.Services.MonitoredRepository? monitored_repo;
+        public bool has_monitored_repo {
+            get {
+                return monitored_repo != null;
+            }
+        }
         // Cache the visible item in the project.
         private List<VisibleItem?> visible_item_list = null;
 
@@ -41,6 +47,7 @@ namespace Scratch.FolderManager {
             }
         }
 
+        public bool is_readonly { get; private set; }
         private Ggit.Repository? git_repo {
             get {
                 return (is_git_repo ? monitored_repo.git_repo : null);
@@ -74,7 +81,7 @@ namespace Scratch.FolderManager {
         }
 
         construct {
-            monitored_repo = Scratch.Services.GitManager.get_instance ().add_project (this);
+            is_readonly = Scratch.Services.GitManager.get_instance ().add_project (this, out monitored_repo);
             notify["name"].connect (branch_or_name_changed);
             if (monitored_repo != null) {
                 checkout_local_branch_action = new SimpleAction.stateful (
@@ -142,7 +149,7 @@ namespace Scratch.FolderManager {
             }
 
             MenuItem set_active_folder_item;
-            if (is_git_repo) {
+            if (is_git_repo && !is_readonly) {
                 set_active_folder_item = new GLib.MenuItem (
                     _("Set as Active Project"),
                     GLib.Action.print_detailed_name (
diff --git a/src/MainWindow.vala b/src/MainWindow.vala
index 10e02af36..f401a9543 100644
--- a/src/MainWindow.vala
+++ b/src/MainWindow.vala
@@ -24,9 +24,12 @@ namespace Scratch {
         public const int FONT_SIZE_MIN = 7;
         private const uint MAX_SEARCH_TEXT_LENGTH = 255;
 
+        public bool is_primary { get; construct; } //TODO should this be mutable?
         public Scratch.Application app { get; private set; }
         public bool restore_docs { get; construct; }
         public RestoreOverride restore_override { get; construct set; }
+        public string active_project_path { get; set; }
+
         public string default_globalsearch_path {
             owned get {
                 if (document_view.current_document != null) {
@@ -35,7 +38,7 @@ namespace Scratch {
                     }
                 }
 
-                return git_manager.active_project_path;
+                return active_project_path;
             }
         }
 
@@ -87,7 +90,6 @@ namespace Scratch {
         public const string ACTION_ADD_MARK = "action_add_mark";
         public const string ACTION_PREVIOUS_MARK = "action_previous_mark";
         public const string ACTION_NEXT_MARK = "action_next_mark";
-
         public const string ACTION_UNDO = "action-undo";
         public const string ACTION_REDO = "action-redo";
         public const string ACTION_REVERT = "action-revert";
@@ -130,14 +132,19 @@ namespace Scratch {
 
         private Services.GitManager git_manager;
 
-        private const ActionEntry[] ACTION_ENTRIES = {
+        private const ActionEntry[] PRIMARY_ONLY_ACTION_ENTRIES = {
             { ACTION_CLONE_REPO, action_clone_repo },
+            { ACTION_OPEN_FOLDER, action_open_folder, "s" },
+            { ACTION_TOGGLE_TERMINAL, action_toggle_terminal, null, "false"},
+            { ACTION_OPEN_IN_TERMINAL, action_open_in_terminal, "s"},
+            { ACTION_NEW_BRANCH, action_new_branch, "s" },
+        };
+        private const ActionEntry[] ACTION_ENTRIES = {
             { ACTION_FIND, action_find, "s"},
             { ACTION_FIND_NEXT, action_find_next },
             { ACTION_FIND_PREVIOUS, action_find_previous },
             { ACTION_FIND_GLOBAL, action_find_global, "s" },
             { ACTION_OPEN, action_open },
-            { ACTION_OPEN_FOLDER, action_open_folder, "s" },
             { ACTION_COLLAPSE_ALL_FOLDERS, action_collapse_all_folders },
             { ACTION_ORDER_FOLDERS, action_order_folders },
             { ACTION_PREFERENCES, action_preferences },
@@ -151,7 +158,6 @@ namespace Scratch {
             { ACTION_NEW_TAB, action_new_tab },
             { ACTION_NEW_FROM_CLIPBOARD, action_new_tab_from_clipboard },
             { ACTION_DUPLICATE_TAB, action_duplicate_tab },
-            { ACTION_PREFERENCES, action_preferences },
             { ACTION_UNDO, action_undo },
             { ACTION_REDO, action_redo },
             { ACTION_SHOW_REPLACE, action_show_replace },
@@ -165,13 +171,10 @@ namespace Scratch {
             { ACTION_ZOOM_OUT, action_zoom_out},
             { ACTION_TOGGLE_COMMENT, action_toggle_comment },
             { ACTION_TOGGLE_SIDEBAR, action_toggle_sidebar, null, "true" },
-            { ACTION_TOGGLE_TERMINAL, action_toggle_terminal, null, "false"},
-            { ACTION_OPEN_IN_TERMINAL, action_open_in_terminal, "s"},
             { ACTION_TOGGLE_OUTLINE, action_toggle_outline, null, "false" },
             { ACTION_NEXT_TAB, action_next_tab },
             { ACTION_PREVIOUS_TAB, action_previous_tab },
             { ACTION_CLEAR_LINES, action_clear_lines },
-            { ACTION_NEW_BRANCH, action_new_branch, "s" },
             { ACTION_ADD_MARK, action_add_mark},
             { ACTION_PREVIOUS_MARK, action_previous_mark},
             { ACTION_NEXT_MARK, action_next_mark},
@@ -186,17 +189,26 @@ namespace Scratch {
             { ACTION_OPEN_IN_NEW_WINDOW, action_open_in_new_window, "s" },
         };
 
-        public MainWindow (bool restore_docs) {
+        public MainWindow.primary () {
+            Object (
+                is_primary: true,
+                icon_name: Constants.PROJECT_NAME,
+                restore_docs: true
+            );
+        }
+        public MainWindow.secondary () {
             Object (
+                is_primary: false,
                 icon_name: Constants.PROJECT_NAME,
-                restore_docs: restore_docs
+                restore_docs: false
             );
         }
 
-        public MainWindow.with_restore_override (bool restore_docs, RestoreOverride restore_override) {
+        public MainWindow.primary_with_restore_override (RestoreOverride restore_override) {
             Object (
+                is_primary: true,
                 icon_name: Constants.PROJECT_NAME,
-                restore_docs: restore_docs,
+                restore_docs: true,
                 restore_override: restore_override
             );
         }
@@ -279,6 +291,9 @@ namespace Scratch {
 
             actions = new SimpleActionGroup ();
             actions.add_action_entries (ACTION_ENTRIES, this);
+            if (is_primary) {
+                actions.add_action_entries (PRIMARY_ONLY_ACTION_ENTRIES, this);
+            }
             insert_action_group (ACTION_GROUP, actions);
 
             foreach (var action in action_accelerators.get_keys ()) {
@@ -349,12 +364,22 @@ namespace Scratch {
             outline_action.set_state (saved_state.get_boolean ("outline-visible"));
             update_toolbar_button (ACTION_TOGGLE_OUTLINE, saved_state.get_boolean ("outline-visible"));
 
-            var terminal_action = Utils.action_from_group (ACTION_TOGGLE_TERMINAL, actions);
-            terminal_action.set_state (saved_state.get_boolean ("terminal-visible"));
-            update_toolbar_button (ACTION_TOGGLE_TERMINAL, saved_state.get_boolean ("terminal-visible"));
+
+            if (is_primary) {
+                var terminal_action = Utils.action_from_group (ACTION_TOGGLE_TERMINAL, actions);
+                terminal_action.set_state (saved_state.get_boolean ("terminal-visible"));
+                update_toolbar_button (ACTION_TOGGLE_TERMINAL, saved_state.get_boolean ("terminal-visible"));
+            } else {
+                terminal.visible = false;
+            }
 
             Unix.signal_add (Posix.Signal.INT, quit_source_func, Priority.HIGH);
             Unix.signal_add (Posix.Signal.TERM, quit_source_func, Priority.HIGH);
+
+            bind_property ("active-project-path", sidebar.choose_project_button, "active-project-path", BIDIRECTIONAL);
+            if (is_primary) {
+                settings.bind ("active-project-path", this, "active-project-path", DEFAULT);
+            }
         }
 
         private void update_style () {
@@ -482,7 +507,7 @@ namespace Scratch {
 
             sidebar = new Code.Sidebar ();
 
-            folder_manager_view = new FolderManager.FileView (plugins);
+            folder_manager_view = new FolderManager.FileView (plugins, is_primary);
 
             sidebar.add_tab (folder_manager_view);
             folder_manager_view.show_all ();
@@ -1012,7 +1037,7 @@ namespace Scratch {
                 return;
             }
 
-            var new_window = new MainWindow (false);
+            var new_window = new MainWindow.secondary ();
             var file = File.new_for_path (path);
             var doc = new Scratch.Services.Document (new_window.actions, file);
 
@@ -1045,8 +1070,8 @@ namespace Scratch {
 
         private void action_clone_repo (SimpleAction action, Variant? param) {
             var default_projects_folder = Scratch.settings.get_string ("default-projects-folder");
-            if (default_projects_folder == "" && git_manager.active_project_path != "") {
-                default_projects_folder = Path.get_dirname (git_manager.active_project_path);
+            if (default_projects_folder == "" && active_project_path != "") {
+                default_projects_folder = Path.get_dirname (active_project_path);
             }
 
             var default_remote = Scratch.settings.get_string ("default-remote");
@@ -1338,7 +1363,7 @@ namespace Scratch {
                 Utils.action_from_group (ACTION_TOGGLE_SHOW_FIND, actions).set_enabled (is_current_doc);
                 Utils.action_from_group (ACTION_FIND_NEXT, actions).set_enabled (is_current_doc);
                 Utils.action_from_group (ACTION_FIND_PREVIOUS, actions).set_enabled (is_current_doc);
-                var can_global_search = is_current_doc || git_manager.active_project_path != null;
+                var can_global_search = is_current_doc || active_project_path != null;
                 Utils.action_from_group (ACTION_FIND_GLOBAL, actions).set_enabled (can_global_search);
 
                 return Source.REMOVE;
@@ -1518,7 +1543,7 @@ namespace Scratch {
              }
 
              if (path == "") { // Happens when keyboard accelerator is used
-                 path = git_manager.active_project_path;
+                 path = active_project_path;
                  if (use_build_dir) {
                      path = git_manager.get_default_build_dir (path);
                  }
diff --git a/src/Services/GitManager.vala b/src/Services/GitManager.vala
index 5b80d3084..04f55e546 100644
--- a/src/Services/GitManager.vala
+++ b/src/Services/GitManager.vala
@@ -21,7 +21,6 @@
 namespace Scratch.Services {
     public class GitManager : Object {
         public ListStore project_liststore { get; private set; }
-        public string active_project_path { get; set; default = "";}
 
         static Gee.HashMap<string, MonitoredRepository> project_gitrepo_map;
         static GitManager? instance;
@@ -47,18 +46,27 @@ namespace Scratch.Services {
         construct {
             // Used to populate the ChooseProject popover in sorted order
             project_liststore = new ListStore (typeof (FolderManager.ProjectFolderItem));
-            settings.bind ("active-project-path", this, "active-project-path", DEFAULT);
         }
 
-        public MonitoredRepository? add_project (FolderManager.ProjectFolderItem root_folder) {
-            var root_path = root_folder.file.file.get_path ();
-            MonitoredRepository? monitored_repo = null;
+        public bool add_project (FolderManager.ProjectFolderItem root_folder, out MonitoredRepository? monitored_repo) {
+            var root_path = root_folder.path;
+            monitored_repo = null;
+            uint position;
+            if (project_liststore.find_with_equal_func (
+                    root_folder,
+                    (a, b) => { return ((FolderManager.Item) a).equal ((FolderManager.Item) b); },
+                    out position
+                )) {
+
+                monitored_repo = project_gitrepo_map.@get (root_path);
+                return true;
+            }
+
             try {
                 var git_repo = Ggit.Repository.open (root_folder.file.file);
                 if (!project_gitrepo_map.has_key (root_path)) {
                     monitored_repo = new MonitoredRepository (git_repo);
                     project_gitrepo_map.@set (root_path, monitored_repo);
-                    return project_gitrepo_map.@get (root_path);
                 }
             } catch (Error e) {
                 debug (
@@ -74,7 +82,8 @@ namespace Scratch.Services {
             }
 
             // No longer need to set default project (restored from settings or left unset)
-            return project_gitrepo_map.@get (root_path);
+            monitored_repo = project_gitrepo_map.@get (root_path);
+            return false;
         }
 
         [CCode (instance_pos = -1)]
@@ -100,17 +109,16 @@ namespace Scratch.Services {
         }
 
         // @project_path is the root of a project or null
-        public string get_default_build_dir (string? project_path) {
-            string build_path = project_path != null ? project_path : active_project_path;
+        public string get_default_build_dir (string project_path) {
             var default_build_dir = Scratch.settings.get_string ("default-build-directory");
-            var build_file = GLib.File.new_for_path (Path.build_filename (build_path, default_build_dir));
+            var build_file = GLib.File.new_for_path (Path.build_filename (project_path, default_build_dir));
             if (build_file.query_exists ()) {
-                build_path = build_file.get_path ();
+                return build_file.get_path ();
             } else {
                 warning ("build path not found %s", build_file.get_path ());
             }
 
-            return build_path;
+            return project_path;
         }
 
         public async bool clone_repository (
diff --git a/src/Widgets/ChooseProjectButton.vala b/src/Widgets/ChooseProjectButton.vala
index 3b035c5b2..5b17c9ed1 100644
--- a/src/Widgets/ChooseProjectButton.vala
+++ b/src/Widgets/ChooseProjectButton.vala
@@ -21,6 +21,7 @@ public class Code.ChooseProjectButton : Gtk.MenuButton {
     private const string PROJECT_TOOLTIP = N_("Active Git Project: %s");
     private Gtk.Label label_widget;
     private Gtk.ListBox project_listbox;
+    public string active_project_path { get; set; }
 
     public signal void project_chosen ();
 
@@ -99,7 +100,16 @@ public class Code.ChooseProjectButton : Gtk.MenuButton {
 
         popover = project_popover;
 
+        // Initialise with any pre-existing projects (needed for second and subsequent window)
         var git_manager = Scratch.Services.GitManager.get_instance ();
+        var src = git_manager.project_liststore;
+        for (int index = 0; index < src.n_items; index++) {
+            var item = src.get_object (index);
+            if (item is Scratch.FolderManager.ProjectFolderItem) {
+                var row = create_project_row ((Scratch.FolderManager.ProjectFolderItem)item);
+                project_listbox.insert (row, index);
+            }
+        }
 
         git_manager.project_liststore.items_changed.connect ((src, pos, n_removed, n_added) => {
             var rows = project_listbox.get_children ();
@@ -119,40 +129,38 @@ public class Code.ChooseProjectButton : Gtk.MenuButton {
 
         project_listbox.remove.connect ((row) => {
             var project_row = row as ProjectRow;
-            var current_project = Scratch.Services.GitManager.get_instance ().active_project_path;
+            var current_project = active_project_path;
             if (project_row.project_path == current_project) {
-                Scratch.Services.GitManager.get_instance ().active_project_path = "";
+                active_project_path = "";
                 // Label and active_path will be updated automatically
             }
         });
 
         project_listbox.row_activated.connect ((row) => {
             var project_entry = ((ProjectRow) row);
-            git_manager.active_project_path = project_entry.project_path;
+            active_project_path = project_entry.project_path;
             project_chosen ();
         });
 
         toggled.connect (() => {
             if (active) {
-                unowned var active_path = Scratch.Services.GitManager.get_instance ().active_project_path;
                 foreach (var child in project_listbox.get_children ()) {
                     var project_row = ((ProjectRow) child);
                     // All paths must not end in directory separator so can be compared directly
-                    project_row.active = active_path == project_row.project_path;
+                    project_row.active = active_project_path == project_row.project_path;
                 }
             }
         });
 
-        git_manager.notify["active-project-path"].connect (update_button);
+        notify["active-project-path"].connect (update_button);
         update_button ();
     }
 
     // Set appearance (only) of project chooser button and list according to active path
     private void update_button () {
-        unowned var active_path = Scratch.Services.GitManager.get_instance ().active_project_path;
-        if (active_path != "") {
-            label_widget.label = Path.get_basename (active_path);
-            tooltip_text = _(PROJECT_TOOLTIP).printf (Scratch.Utils.replace_home_with_tilde (active_path));
+        if (active_project_path != "") {
+            label_widget.label = Path.get_basename (active_project_path);
+            tooltip_text = _(PROJECT_TOOLTIP).printf (Scratch.Utils.replace_home_with_tilde (active_project_path));
         } else {
             label_widget.label = Path.get_basename (_(NO_PROJECT_SELECTED));
             tooltip_text = _(PROJECT_TOOLTIP).printf (_(NO_PROJECT_SELECTED));
diff --git a/src/Widgets/DocumentView.vala b/src/Widgets/DocumentView.vala
index 30fa7f56c..9cdc7eb0f 100644
--- a/src/Widgets/DocumentView.vala
+++ b/src/Widgets/DocumentView.vala
@@ -219,7 +219,7 @@ public class Scratch.Widgets.DocumentView : Gtk.Box {
             return;
         }
 
-        var new_window = new MainWindow (false);
+        var new_window = new MainWindow.secondary ();
         tab_view.transfer_page (target, new_window.document_view.tab_view, 0);
     }
 
@@ -546,7 +546,7 @@ public class Scratch.Widgets.DocumentView : Gtk.Box {
     }
 
     private unowned Hdy.TabView? on_doc_to_new_window (Hdy.TabView tab_view) {
-        var other_window = new MainWindow (false);
+        var other_window = new MainWindow.secondary ();
         return other_window.document_view.tab_view;
     }