diff --git a/src/app/mod.rs b/src/app/mod.rs
index acf0f920b..82f8c8d77 100644
--- a/src/app/mod.rs
+++ b/src/app/mod.rs
@@ -1767,6 +1767,9 @@ pub enum Message {
     OptionsThemeChanged(String),
     /// Edit one of Custom theme's six base colours as #RRGGBB.
     OptionsThemeColorChanged(usize, String),
+    /// Register or unregister as the .dwg/.dxf handler, from Options. Same
+    /// setting the FILEASSOC command carries.
+    FileAssocChanged(bool),
     /// Switch the interface language and redraw localized views.
     LanguageChanged(crate::i18n::Language),
     /// Drop every entity from the active drawing.
diff --git a/src/app/update/mod.rs b/src/app/update/mod.rs
index cab874d5e..b70f2fc0f 100644
--- a/src/app/update/mod.rs
+++ b/src/app/update/mod.rs
@@ -5087,6 +5087,39 @@ impl OpenCADStudio {
                 Task::none()
             }
 
+            Message::FileAssocChanged(enabled) => {
+                // The same two calls FILEASSOC makes, so the checkbox and the
+                // command cannot leave the setting and the registration
+                // disagreeing.
+                self.file_assoc_enabled = enabled;
+                self.persist_settings_if_changed();
+                let outcome = if enabled {
+                    crate::io::file_association::register_as_handler()
+                } else {
+                    crate::io::file_association::unregister_handler()
+                };
+                match outcome {
+                    Ok(()) => {
+                        let said = if enabled {
+                            crate::t!("Registered as a .dwg/.dxf handler.")
+                        } else {
+                            crate::t!("No longer registered as a file handler.")
+                        };
+                        self.command_line.push_output(said.as_ref());
+                    }
+                    Err(why) => {
+                        // The setting is what the user asked for; the
+                        // registration is what the system allowed. Put the
+                        // checkbox back rather than showing a state that is not
+                        // true.
+                        self.file_assoc_enabled = !enabled;
+                        self.persist_settings_if_changed();
+                        self.command_line
+                            .push_error(crate::tf!("File association failed: {why}").as_ref());
+                    }
+                }
+                Task::none()
+            }
             Message::LanguageChanged(language) => {
                 if self.language == language {
                     return Task::none();
diff --git a/src/app/view/modal.rs b/src/app/view/modal.rs
index 7bc788519..71a2b1de6 100644
--- a/src/app/view/modal.rs
+++ b/src/app/view/modal.rs
@@ -91,6 +91,7 @@ impl OpenCADStudio {
                 |flow| {
                     crate::ui::window::options::view_window(
                         &self.default_save_format,
+                        self.file_assoc_enabled,
                         &self.ui_theme,
                         &self.theme_color_inputs,
                         self.language,
diff --git a/src/ui/window/options.rs b/src/ui/window/options.rs
index 04fbbf544..cb27fd43c 100644
--- a/src/ui/window/options.rs
+++ b/src/ui/window/options.rs
@@ -20,6 +20,7 @@ impl<T> fmt::Display for Labelled<T> {
 
 pub fn view_window<'a>(
     default_save_format: &'a str,
+    file_assoc_enabled: bool,
     ui_theme: &'a UiThemeConfig,
     theme_color_inputs: &'a [String; 6],
     language: crate::i18n::Language,
@@ -137,6 +138,22 @@ pub fn view_window<'a>(
         text(crate::tr!("options-default-save-format-help"))
         .size(11)
         .width(sizing.width),
+        Space::new().height(14),
+        row![
+            iced::widget::checkbox(file_assoc_enabled)
+                .on_toggle(Message::FileAssocChanged)
+                .size(15),
+            text(crate::t!("Open .dwg and .dxf files with Open CAD Studio"))
+                .size(12),
+        ]
+        .spacing(8)
+        .align_y(iced::Center),
+        Space::new().height(6),
+        text(crate::t!(
+            "Also installs the application and file-type icons the desktop shows."
+        ))
+        .size(11)
+        .width(sizing.width),
         Space::new().height(22),
         text(crate::tr!("options-theme-section")).size(15),
         Space::new().height(10),