diff --git a/src/widget.rs b/src/widget.rs
index 73aa0fd..17c7331 100644
--- a/src/widget.rs
+++ b/src/widget.rs
@@ -1728,7 +1728,7 @@ impl<T, R> SharedCallback<T, R> {
     where
         F: FnMut(T) -> R + Send + 'static,
     {
-        Self(Arc::new(Mutex::new(Callback::new(function))))
+        Self::from(Callback::new(function))
     }
 
     /// Invokes the wrapped function and returns the produced value.
@@ -1759,6 +1759,12 @@ impl<T, R> Clone for SharedCallback<T, R> {
     }
 }
 
+impl<T, R> From<Callback<T, R>> for SharedCallback<T, R> {
+    fn from(callback: Callback<T, R>) -> Self {
+        Self(Arc::new(Mutex::new(callback)))
+    }
+}
+
 /// A function that can be invoked once with a parameter (`T`) and returns `R`.
 ///
 /// This type is used by widgets to signal an event that can happen only onceq.
diff --git a/src/widgets/layers.rs b/src/widgets/layers.rs
index ba37ba9..f666b52 100644
--- a/src/widgets/layers.rs
+++ b/src/widgets/layers.rs
@@ -1,7 +1,6 @@
 //! Widgets that stack in the Z-direction.
 
 use std::fmt::{self, Debug};
-use std::sync::Arc;
 use std::time::Duration;
 
 use alot::{LotId, OrderedLots};
@@ -10,15 +9,14 @@ use easing_function::EasingFunction;
 use figures::units::{Lp, Px, UPx};
 use figures::{IntoSigned, IntoUnsigned, Point, Rect, Size, Zero};
 use intentional::Assert;
-use parking_lot::Mutex;
 
 use crate::animation::{AnimationHandle, AnimationTarget, IntoAnimate, Spawn, ZeroToOne};
 use crate::context::{AsEventContext, EventContext, GraphicsContext, LayoutContext, Trackable};
 use crate::styles::components::EasingIn;
 use crate::value::{Destination, Dynamic, DynamicGuard, IntoValue, Source, Value};
 use crate::widget::{
-    Callback, MakeWidget, MountedChildren, MountedWidget, Widget, WidgetId, WidgetList, WidgetRef,
-    WrapperWidget,
+    Callback, MakeWidget, MountedChildren, MountedWidget, SharedCallback, Widget, WidgetId,
+    WidgetList, WidgetRef, WrapperWidget,
 };
 use crate::widgets::container::ContainerShadow;
 use crate::ConstraintLimit;
@@ -671,7 +669,7 @@ impl Overlayable for OverlayBuilder<'_> {
     }
 
     fn on_dismiss(mut self, callback: Callback) -> Self {
-        self.layout.on_dismiss = Some(Arc::new(Mutex::new(callback)));
+        self.layout.on_dismiss = Some(SharedCallback::from(callback));
         self
     }
 
@@ -707,13 +705,12 @@ struct OverlayLayout {
     positioning: Position<Px>,
     requires_hover: bool,
     layout: Option<Rect<Px>>,
-    on_dismiss: Option<Arc<Mutex<Callback>>>,
+    on_dismiss: Option<SharedCallback>,
 }
 
 impl Drop for OverlayLayout {
     fn drop(&mut self) {
         if let Some(on_dismiss) = &self.on_dismiss {
-            let mut on_dismiss = on_dismiss.lock();
             on_dismiss.invoke(());
         }
     }
@@ -729,11 +726,7 @@ impl PartialEq for OverlayLayout {
             && self.positioning == other.positioning
             && self.requires_hover == other.requires_hover
             && self.layout == other.layout
-            && match (&self.on_dismiss, &other.on_dismiss) {
-                (Some(this), Some(other)) => Arc::ptr_eq(this, other),
-                (None, None) => true,
-                _ => false,
-            }
+            && self.on_dismiss == other.on_dismiss
     }
 }
 
diff --git a/src/widgets/menu.rs b/src/widgets/menu.rs
index 0a2340c..2cdc1cf 100644
--- a/src/widgets/menu.rs
+++ b/src/widgets/menu.rs
@@ -9,7 +9,6 @@ use figures::units::{Lp, Px, UPx};
 use figures::{Angle, IntoSigned, Point, Rect, Round, ScreenScale, Size, Zero};
 use kludgine::shapes::{PathBuilder, Shape, StrokeOptions};
 use kludgine::DrawableExt;
-use parking_lot::Mutex;
 
 use self::sealed::{SharedMenuState, SubmenuFactory};
 use super::button::{ButtonColors, ButtonKind, VisualState};
@@ -25,8 +24,8 @@ use crate::styles::components::{
 use crate::styles::Styles;
 use crate::value::{Dynamic, IntoValue, Source, Value};
 use crate::widget::{
-    Callback, EventHandling, MakeWidget, MakeWidgetWithTag, Widget, WidgetId, WidgetInstance,
-    WidgetRef, WidgetTag, HANDLED,
+    Callback, EventHandling, MakeWidget, MakeWidgetWithTag, SharedCallback, Widget, WidgetId,
+    WidgetInstance, WidgetRef, WidgetTag, HANDLED,
 };
 use crate::ConstraintLimit;
 
@@ -78,7 +77,7 @@ where
     {
         Menu {
             items: self.items,
-            on_click: MenuHandler(Arc::new(Mutex::new(Callback::new(selected)))),
+            on_click: MenuHandler(SharedCallback::new(selected)),
         }
     }
 }
@@ -450,7 +449,7 @@ where
 
 /// A handler for a selected [`MenuItem<T>`].
 #[derive(Debug, Clone)]
-pub struct MenuHandler<T>(Arc<Mutex<Callback<T>>>);
+pub struct MenuHandler<T>(SharedCallback<T>);
 
 #[derive(Debug)]
 struct OpenMenu<T> {
@@ -759,7 +758,7 @@ where
             let ItemKind::Item(item) = &self.items[index].item else {
                 return;
             };
-            self.on_click.0.lock().invoke(item.value.clone());
+            self.on_click.0.invoke(item.value.clone());
             let mut shared = self.shared.lock();
             for handle in shared.open_menus.drain() {
                 handle.dismiss();
diff --git a/src/window.rs b/src/window.rs
index bfcf19c..0b1f1d5 100644
--- a/src/window.rs
+++ b/src/window.rs
@@ -61,7 +61,7 @@ use crate::value::{
     Destination, Dynamic, DynamicReader, IntoDynamic, IntoValue, Source, Tracked, Value,
 };
 use crate::widget::{
-    Callback, EventHandling, MakeWidget, MountedWidget, OnceCallback, RootBehavior, WidgetId,
+    EventHandling, MakeWidget, MountedWidget, OnceCallback, RootBehavior, SharedCallback, WidgetId,
     WidgetInstance, HANDLED, IGNORED,
 };
 use crate::window::sealed::WindowCommand;
@@ -287,7 +287,7 @@ pub struct RunningWindow<W> {
     focused: Dynamic<bool>,
     occluded: Dynamic<bool>,
     inner_size: Dynamic<Size<UPx>>,
-    close_requested: Option<Arc<Mutex<Callback<(), bool>>>>,
+    close_requested: Option<SharedCallback<(), bool>>,
 }
 
 impl<W> RunningWindow<W>
@@ -303,7 +303,7 @@ where
         focused: &Dynamic<bool>,
         occluded: &Dynamic<bool>,
         inner_size: &Dynamic<Size<UPx>>,
-        close_requested: &Option<Arc<Mutex<Callback<(), bool>>>>,
+        close_requested: &Option<SharedCallback<(), bool>>,
     ) -> Self {
         Self {
             window,
@@ -544,7 +544,7 @@ where
     outer_size: Option<Dynamic<Size<UPx>>>,
     inner_position: Option<Dynamic<Point<Px>>>,
     outer_position: Option<Dynamic<Point<Px>>>,
-    close_requested: Option<Callback<(), bool>>,
+    close_requested: Option<SharedCallback<(), bool>>,
     icon: Option<Value<Option<RgbaImage>>>,
     modifiers: Option<Dynamic<Modifiers>>,
     enabled_buttons: Option<Value<WindowButtons>>,
@@ -990,7 +990,7 @@ where
     where
         Function: FnMut(()) -> bool + Send + 'static,
     {
-        self.close_requested = Some(Callback::new(on_close_requested));
+        self.close_requested = Some(SharedCallback::new(on_close_requested));
         self
     }
 
@@ -1072,7 +1072,7 @@ where
                     cursive_font_family: this.cursive_font_family,
                     vsync: this.vsync,
                     multisample_count: this.multisample_count,
-                    close_requested: this.close_requested.map(|cb| Arc::new(Mutex::new(cb))),
+                    close_requested: this.close_requested,
                     zoom: this.zoom.unwrap_or_else(|| Dynamic::new(Fraction::ONE)),
                     resize_to_fit: this.resize_to_fit,
                     content_protected: this.content_protected.unwrap_or_default(),
@@ -1237,7 +1237,7 @@ struct OpenWindow<T> {
     vsync: bool,
     dpi_scale: Dynamic<Fraction>,
     zoom: Tracked<Dynamic<Fraction>>,
-    close_requested: Option<Arc<Mutex<Callback<(), bool>>>>,
+    close_requested: Option<SharedCallback<(), bool>>,
     content_protected: Tracked<Value<bool>>,
     cursor_hittest: Tracked<Value<bool>>,
     cursor_visible: Tracked<Value<bool>>,
@@ -1269,8 +1269,8 @@ where
         *should_close |= behavior.close_requested(window)
             && window
                 .close_requested
-                .as_mut()
-                .map_or(true, |close| close.lock().invoke(()));
+                .as_ref()
+                .map_or(true, |close| close.invoke(()));
 
         *should_close
     }
@@ -2723,7 +2723,6 @@ pub(crate) struct CursorState {
 pub(crate) mod sealed {
     use std::cell::RefCell;
     use std::num::NonZeroU32;
-    use std::sync::Arc;
 
     use figures::units::{Px, UPx};
     use figures::{Fraction, Point, Size};
@@ -2731,7 +2730,6 @@ pub(crate) mod sealed {
     use kludgine::app::winit::event::Modifiers;
     use kludgine::app::winit::window::{Fullscreen, UserAttentionType, WindowButtons, WindowLevel};
     use kludgine::Color;
-    use parking_lot::Mutex;
 
     use super::{PendingWindow, WindowHandle};
     use crate::app::Cushy;
@@ -2739,7 +2737,7 @@ pub(crate) mod sealed {
     use crate::fonts::FontCollection;
     use crate::styles::{FontFamilyList, ThemePair};
     use crate::value::{Dynamic, Value};
-    use crate::widget::{Callback, OnceCallback};
+    use crate::widget::{OnceCallback, SharedCallback};
     use crate::window::{ThemeMode, WindowAttributes};
 
     pub struct Context<C> {
@@ -2771,7 +2769,7 @@ pub(crate) mod sealed {
         pub vsync: bool,
         pub multisample_count: NonZeroU32,
         pub resize_to_fit: Value<bool>,
-        pub close_requested: Option<Arc<Mutex<Callback<(), bool>>>>,
+        pub close_requested: Option<SharedCallback<(), bool>>,
         pub content_protected: Value<bool>,
         pub cursor_hittest: Value<bool>,
         pub cursor_visible: Value<bool>,