diff --git a/Sources/Gtk/Utility/GActionMap.swift b/Sources/Gtk/Utility/GActionMap.swift
index b2721c55513..d43098ed3ca 100644
--- a/Sources/Gtk/Utility/GActionMap.swift
+++ b/Sources/Gtk/Utility/GActionMap.swift
@@ -8,9 +8,4 @@ extension GActionMap {
     public func addAction(_ action: any GAction) {
         g_action_map_add_action(actionMapPointer, action.actionPointer)
     }
-
-    public func addAction(named name: String, action: @escaping () -> Void) {
-        let simpleAction = GSimpleAction(name: name, action: action)
-        addAction(simpleAction)
-    }
 }
diff --git a/Sources/Gtk/Utility/GSimpleAction.swift b/Sources/Gtk/Utility/GSimpleAction.swift
index 12a2d3db9ab..b201f161741 100644
--- a/Sources/Gtk/Utility/GSimpleAction.swift
+++ b/Sources/Gtk/Utility/GSimpleAction.swift
@@ -9,42 +9,63 @@ public class GSimpleAction: GAction, GObjectRepresentable {
 
     @GObjectProperty(named: "enabled") var enabled: Bool
 
-    private class Action {
-        var run: () -> Void
-
-        init(_ action: @escaping () -> Void) {
-            run = action
-        }
+    private class Box<T> {
+        var value: T
+        init(_ value: T) { self.value = value }
     }
 
     public init(name: String, action: @escaping () -> Void) {
         actionPointer = g_simple_action_new(name, nil)
 
-        let wrappedAction = Action(action)
+        connectActionSignal(Box(action)) { _, _, data in
+            let action = Unmanaged<Box<() -> Void>>.fromOpaque(data).takeUnretainedValue()
+            action.value()
+        }
+    }
+
+    public init(name: String, state: Bool, action: @escaping (Bool) -> Void) {
+        actionPointer = g_simple_action_new_stateful(
+            name,
+            nil,
+            g_variant_new_boolean(state.toGBoolean())
+        )
+
+        connectActionSignal(Box(action)) { actionPointer, _, data in
+            // Get the current state...
+            let stateVariant = g_action_get_state(OpaquePointer(actionPointer))
+            let state = g_variant_get_boolean(stateVariant).toBool()
 
-        let handler:
+            // ...toggle it...
+            let newState = !state
+            g_simple_action_set_state(
+                OpaquePointer(actionPointer),
+                g_variant_new_boolean(newState.toGBoolean())
+            )
+
+            // ...then get the action and call it with the new state.
+            let action = Unmanaged<Box<(Bool) -> Void>>.fromOpaque(data).takeUnretainedValue()
+            action.value(newState)
+        }
+    }
+
+    private func connectActionSignal(
+        _ value: some AnyObject,
+        handler:
             @convention(c) (
                 UnsafeMutableRawPointer,
                 OpaquePointer,
                 UnsafeMutableRawPointer
-            ) -> Void =
-                { _, _, data in
-                    let action = Unmanaged<Action>.fromOpaque(data)
-                        .takeUnretainedValue()
-                    action.run()
-                }
-
+            ) -> Void
+    ) {
         g_signal_connect_data(
             UnsafeMutableRawPointer(actionPointer),
             "activate",
             gCallback(handler),
-            Unmanaged<Action>.passRetained(wrappedAction).toOpaque(),
+            Unmanaged.passRetained(value).toOpaque(),
             { data, _ in
-                Unmanaged<Action>.fromOpaque(data!).release()
+                Unmanaged<AnyObject>.fromOpaque(data!).release()
             },
             G_CONNECT_AFTER
         )
     }
-
-    public func registerSignals() {}
 }
diff --git a/Sources/Gtk3/Utility/GActionMap.swift b/Sources/Gtk3/Utility/GActionMap.swift
index 6d38cdc43c8..d4ac14d4098 100644
--- a/Sources/Gtk3/Utility/GActionMap.swift
+++ b/Sources/Gtk3/Utility/GActionMap.swift
@@ -8,9 +8,4 @@ extension GActionMap {
     public func addAction(_ action: any GAction) {
         g_action_map_add_action(actionMapPointer, action.actionPointer)
     }
-
-    public func addAction(named name: String, action: @escaping () -> Void) {
-        let simpleAction = GSimpleAction(name: name, action: action)
-        addAction(simpleAction)
-    }
 }
diff --git a/Sources/Gtk3/Utility/GSimpleAction.swift b/Sources/Gtk3/Utility/GSimpleAction.swift
index d73475bfa93..e2c00e31c9c 100644
--- a/Sources/Gtk3/Utility/GSimpleAction.swift
+++ b/Sources/Gtk3/Utility/GSimpleAction.swift
@@ -9,38 +9,61 @@ public class GSimpleAction: GAction, GObjectRepresentable {
 
     @GObjectProperty(named: "enabled") var enabled: Bool
 
-    private class Action {
-        var run: () -> Void
-
-        init(_ action: @escaping () -> Void) {
-            run = action
-        }
+    private class Box<T> {
+        var value: T
+        init(_ value: T) { self.value = value }
     }
 
     public init(name: String, action: @escaping () -> Void) {
         actionPointer = g_simple_action_new(name, nil)
 
-        let wrappedAction = Action(action)
+        connectActionSignal(Box(action)) { _, _, data in
+            let action = Unmanaged<Box<() -> Void>>.fromOpaque(data).takeUnretainedValue()
+            action.value()
+        }
+    }
+
+    public init(name: String, state: Bool, action: @escaping (Bool) -> Void) {
+        actionPointer = g_simple_action_new_stateful(
+            name,
+            nil,
+            g_variant_new_boolean(state.toGBoolean())
+        )
+
+        connectActionSignal(Box(action)) { actionPointer, _, data in
+            // Get the current state...
+            let stateVariant = g_action_get_state(OpaquePointer(actionPointer))
+            let state = g_variant_get_boolean(stateVariant).toBool()
+
+            // ...toggle it...
+            let newState = !state
+            g_simple_action_set_state(
+                OpaquePointer(actionPointer),
+                g_variant_new_boolean(newState.toGBoolean())
+            )
 
-        let handler:
-            @convention(c) (
-                UnsafeMutableRawPointer,
-                OpaquePointer,
-                UnsafeMutableRawPointer
-            ) -> Void =
-                { _, _, data in
-                    let action = Unmanaged<Action>.fromOpaque(data)
-                        .takeUnretainedValue()
-                    action.run()
-                }
+            // ...then get the action and call it with the new state.
+            let action = Unmanaged<Box<(Bool) -> Void>>.fromOpaque(data).takeUnretainedValue()
+            action.value(newState)
+        }
+    }
 
+    private func connectActionSignal(
+        _ value: some AnyObject,
+        handler:
+        @convention(c) (
+            UnsafeMutableRawPointer,
+            OpaquePointer,
+            UnsafeMutableRawPointer
+        ) -> Void
+    ) {
         g_signal_connect_data(
             UnsafeMutableRawPointer(actionPointer),
             "activate",
             gCallback(handler),
-            Unmanaged<Action>.passRetained(wrappedAction).toOpaque(),
+            Unmanaged.passRetained(value).toOpaque(),
             { data, _ in
-                Unmanaged<Action>.fromOpaque(data!).release()
+                Unmanaged<AnyObject>.fromOpaque(data!).release()
             },
             G_CONNECT_AFTER
         )
diff --git a/Sources/Gtk3Backend/Gtk3Backend.swift b/Sources/Gtk3Backend/Gtk3Backend.swift
index a0e977aafb9..542476e1ea8 100644
--- a/Sources/Gtk3Backend/Gtk3Backend.swift
+++ b/Sources/Gtk3Backend/Gtk3Backend.swift
@@ -240,13 +240,16 @@ public final class Gtk3Backend: AppBackend {
             switch item {
                 case .button(let label, let action):
                     if let action {
-                        actionMap.addAction(named: actionName, action: action)
+                        actionMap.addAction(GSimpleAction(name: actionName, action: action))
                     }
 
                     model.appendItem(label: label, actionName: "\(actionNamespace).\(actionName)")
                 case .toggle(let label, let value, let onChange):
-                    // FIXME: Implement
-                    logger.warning("menu toggles not implemented")
+                    actionMap.addAction(
+                        GSimpleAction(name: actionName, state: value, action: onChange)
+                    )
+
+                    model.appendItem(label: label, actionName: "\(actionNamespace).\(actionName)")
                 case .submenu(let submenu):
                     model.appendSubmenu(
                         label: submenu.label,
diff --git a/Sources/GtkBackend/GtkBackend.swift b/Sources/GtkBackend/GtkBackend.swift
index af4e733ce91..d074dc532b7 100644
--- a/Sources/GtkBackend/GtkBackend.swift
+++ b/Sources/GtkBackend/GtkBackend.swift
@@ -275,13 +275,16 @@ public final class GtkBackend: AppBackend {
             switch item {
                 case .button(let label, let action):
                     if let action {
-                        actionMap.addAction(named: actionName, action: action)
+                        actionMap.addAction(GSimpleAction(name: actionName, action: action))
                     }
 
                     model.appendItem(label: label, actionName: "\(actionNamespace).\(actionName)")
                 case .toggle(let label, let value, let onChange):
-                    // FIXME: Implement
-                    logger.warning("menu toggles not implemented")
+                    actionMap.addAction(
+                        GSimpleAction(name: actionName, state: value, action: onChange)
+                    )
+
+                    model.appendItem(label: label, actionName: "\(actionNamespace).\(actionName)")
                 case .submenu(let submenu):
                     model.appendSubmenu(
                         label: submenu.label,