diff --git a/README.md b/README.md
index 11e61e441e7303e6b0882e12039769fea1a00fcf..ebfc472c5e199049f9122d4703ad9dcbccfa8596 100644
--- a/README.md
+++ b/README.md
@@ -102,7 +102,7 @@ You can find everything you need at: [l10n.gnome.org/module/PasswordSafe/](https
 # Data protection
 Please be careful when using development versions. Create enough backups if you're using a production database with a Password Safe development version. It is possible that data loss will occur, though I give my best that this will never happen.
 
-Development versions create a backup of your database on unlocking by default. These can be found at ```~/.cache/passwordsafe/backup/``` where every backup is named by database name and date. If you don't want this behavior you can turn it off via dconf:
+Development versions create a backup of your database on unlocking by default. These can be found at ```$XDG_CACHE_HOME/passwordsafe/backup/``` (or `~/.var/app/org.gnome.PasswordSafe/cache/passwordsafe/backup` for Flatpak users) where every backup is named by database name and date. If you don't want this behavior you can turn it off via dconf:
 ```
 gsettings set org.gnome.PasswordSafe development-backup-mode false
 ```
diff --git a/flatpak/org.gnome.PasswordSafe.json b/flatpak/org.gnome.PasswordSafe.json
index a546e4d132149527b204fc6182ac0d0c8b337fa1..8f1c41b4d8387b383a262d0778962e27c5a144c2 100644
--- a/flatpak/org.gnome.PasswordSafe.json
+++ b/flatpak/org.gnome.PasswordSafe.json
@@ -15,7 +15,6 @@
         "--socket=fallback-x11",
         "--socket=wayland",
         "--filesystem=xdg-run/gvfs",
-        "--filesystem=/tmp",
         "--metadata=X-DConf=migrate-path=/org/gnome/PasswordSafeDevel/",
         "--talk-name=org.gtk.vfs",
         "--talk-name=org.gtk.vfs.*"
diff --git a/passwordsafe/attachment_warning_dialog.py b/passwordsafe/attachment_warning_dialog.py
index 079da0c25576dfb4e22f732e0291d6268f20446b..ef5a141e8cbbeb817c3dd7955bab85119dc28df2 100644
--- a/passwordsafe/attachment_warning_dialog.py
+++ b/passwordsafe/attachment_warning_dialog.py
@@ -1,10 +1,11 @@
 # SPDX-License-Identifier: GPL-3.0-only
 from __future__ import annotations
 
-import subprocess
+import logging
+import os
 import typing
 
-from gi.repository import Gio, GLib, Gtk
+from gi.repository import Gdk, Gio, GLib, Gtk
 
 if typing.TYPE_CHECKING:
     from pykeepass.attachment import Attachment
@@ -22,6 +23,7 @@ class AttachmentWarningDialog(Gtk.MessageDialog):
         :param entry_page: entry page
         """
         super().__init__()
+
         self.__unlocked_database = entry_page.unlocked_database
         self.__attachment = attachment
 
@@ -43,8 +45,22 @@ class AttachmentWarningDialog(Gtk.MessageDialog):
         )
 
     def __open_tmp_file(self, bytes_buffer, filename):
-        (file, stream) = Gio.File.new_tmp(filename + ".XXXXXX")
-        stream.get_output_stream().write_bytes(GLib.Bytes.new(bytes_buffer))
-        stream.close()
-        self.__unlocked_database.scheduled_tmpfiles_deletion.append(file)
-        subprocess.run(["xdg-open", file.get_path()], check=True)
+        try:
+            cache_dir = os.path.join(
+                GLib.get_user_cache_dir(), "passwordsafe", "tmp"
+            )
+            file_path = os.path.join(cache_dir, filename)
+            if not os.path.exists(cache_dir):
+                os.makedirs(cache_dir)
+
+            gfile = Gio.File.new_for_path(file_path)
+            output_stream = gfile.replace(
+                None, False,
+                Gio.FileCreateFlags.PRIVATE
+                | Gio.FileCreateFlags.REPLACE_DESTINATION, None
+            )
+            output_stream.write_bytes(GLib.Bytes.new(bytes_buffer))
+            output_stream.close()
+            Gtk.show_uri_on_window(None, gfile.get_uri(), Gdk.CURRENT_TIME)
+        except GLib.Error as err:
+            logging.debug("Could not load attachment %s: %s", filename, err)
diff --git a/passwordsafe/unlock_database.py b/passwordsafe/unlock_database.py
index 05d30619b4a20d8b7aff8e25da6a0728079db894..d1528b2ccad62b8e65e23d305e0714569a4499ba 100644
--- a/passwordsafe/unlock_database.py
+++ b/passwordsafe/unlock_database.py
@@ -430,7 +430,9 @@ class UnlockDatabase:
         passwordsafe.config_manager.set_last_opened_database(opened.get_uri())
 
         if passwordsafe.config_manager.get_development_backup_mode():
-            cache_dir = os.path.expanduser("~") + "/.cache/passwordsafe/backup"
+            cache_dir = os.path.join(
+                GLib.get_user_cache_dir(), "passwordsafe", "backup"
+            )
             if not os.path.exists(cache_dir):
                 os.makedirs(cache_dir)
 
diff --git a/passwordsafe/unlocked_database.py b/passwordsafe/unlocked_database.py
index d287214b7ce320e07713cf7efcec95119189cc32..feeed621c5592eeaad04cf91d4cacf4ff2d19ace 100644
--- a/passwordsafe/unlocked_database.py
+++ b/passwordsafe/unlocked_database.py
@@ -1,6 +1,8 @@
 # SPDX-License-Identifier: GPL-3.0-only
 from __future__ import annotations
 
+import os
+import shutil
 import logging
 import threading
 import typing
@@ -48,7 +50,6 @@ class UnlockedDatabase(GObject.GObject):
 
     # Objects
     builder = NotImplemented
-    scheduled_tmpfiles_deletion: list[Gio.File] = []
     clipboard = NotImplemented
     clipboard_timer_handler: int | None = None
     _current_element: SafeElement | None = None
@@ -528,18 +529,7 @@ class UnlockedDatabase(GObject.GObject):
     def _on_database_lock_changed(self, _database_manager, _value):
         locked = self.database_manager.props.locked
         if locked:
-            self.cleanup(False)
-
-            for tmpfile in self.scheduled_tmpfiles_deletion:
-                try:
-                    tmpfile.delete()
-                except GLib.Error as exc:
-                    logging.warning(
-                        "Skipping deletion of tmpfile %s: %s",
-                        tmpfile.get_path(),
-                        exc.message,
-                    )
-
+            self.cleanup()
             if passwordsafe.config_manager.get_save_automatically():
                 self.save_database()
 
@@ -560,13 +550,12 @@ class UnlockedDatabase(GObject.GObject):
     # Helper Methods
     #
 
-    def cleanup(self, delete_tmp_file: bool = True) -> None:
+    def cleanup(self) -> None:
         """Stop all ongoing operations:
 
         * stop the save loop
         * cancel all timers
         * unregistrer from dbus
-        * delete all temporary file is delete_tmp_file is True
 
         :param bool show_save_dialog: chooe to delete temporary files
         """
@@ -590,14 +579,9 @@ class UnlockedDatabase(GObject.GObject):
             GLib.source_remove(self.save_loop)
             self.save_loop = None
 
-        if not delete_tmp_file:
-            return
-
-        for tmpfile in self.scheduled_tmpfiles_deletion:
-            try:
-                tmpfile.delete()
-            except Gio.Error:
-                logging.warning("Skipping deletion of tmpfile...")
+        # Cleanup temporal files created when opening attachments.
+        cache_dir = os.path.join(GLib.get_user_cache_dir(), "passwordsafe", "tmp")
+        shutil.rmtree(cache_dir, ignore_errors=True)
 
     def save_database(self, notification: bool = False) -> None:
         """Save the database.