diff --git a/CHANGELOG.md b/CHANGELOG.md
index e30422a..b2fdf37 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Some signals weren't properly renamed from the previous GTK3 migration (@MightyCreak)
 - The syntax menu wasn't working anymore (@MightyCreak)
 - Properly handles SIGINT (i.e. Ctrl+C) now (@MightyCreak)
+- Add back `save_state()` to remember window's width and height (@MightyCreak)
 
 ## 0.8.1 - 2023-04-07
 
diff --git a/src/diffuse/main.py b/src/diffuse/main.py
index befa6b4..6454225 100644
--- a/src/diffuse/main.py
+++ b/src/diffuse/main.py
@@ -43,6 +43,8 @@ class DiffuseApplication(Gtk.Application):
         self.window = None
         self.sysconfigdir = sysconfigdir
 
+        self.connect('shutdown', self.on_shutdown)
+
         self.add_main_option(
             'version',
             ord('v'),
@@ -249,7 +251,7 @@ also retrieve revisions of files from several VCSs for comparison and merging.''
 
         # load state
         self.statepath = os.path.join(data_dir, 'state')
-        diff_window.loadState(self.statepath)
+        diff_window.load_state(self.statepath)
 
         # process remaining command line arguments
         encoding = None
@@ -366,6 +368,9 @@ also retrieve revisions of files from several VCSs for comparison and merging.''
         self.activate()
         return 0
 
+    def on_shutdown(self, application: Gio.Application) -> None:
+        self.window.save_state(self.statepath)
+
 
 def main(version: str, sysconfigdir: str) -> int:
     """The application's entry point."""
diff --git a/src/diffuse/window.py b/src/diffuse/window.py
index 7f6e53a..58b1073 100644
--- a/src/diffuse/window.py
+++ b/src/diffuse/window.py
@@ -985,7 +985,7 @@ class DiffuseWindow(Gtk.ApplicationWindow):
                     page.open_file(f, True)
 
     # record the window's position and size
-    def configure_cb(self, widget, event):
+    def configure_cb(self, widget: Gtk.Widget, event: Gdk.EventConfigure) -> None:
         # read the state directly instead of using window_maximized as the order
         # of configure/window_state events is undefined
         if (widget.get_window().get_state() & Gdk.WindowState.MAXIMIZED) == 0:
@@ -1000,7 +1000,7 @@ class DiffuseWindow(Gtk.ApplicationWindow):
         )
 
     # load state information that should persist across sessions
-    def loadState(self, statepath: str) -> None:
+    def load_state(self, statepath: str) -> None:
         if os.path.isfile(statepath):
             try:
                 f = open(statepath, 'r')
@@ -1030,7 +1030,7 @@ class DiffuseWindow(Gtk.ApplicationWindow):
             self.maximize()
 
     # save state information that should persist across sessions
-    def saveState(self, statepath: str) -> None:
+    def save_state(self, statepath: str) -> None:
         try:
             ss = []
             for k, v in self.bool_state.items():