diff --git a/crates/engine/src/tests_disk_cache.rs b/crates/engine/src/tests_disk_cache.rs
index 3091964ad..9c4daa954 100644
--- a/crates/engine/src/tests_disk_cache.rs
+++ b/crates/engine/src/tests_disk_cache.rs
@@ -136,3 +136,23 @@ fn footage_changes_change_the_salt() {
     assert_ne!(k3, k2);
     assert_ne!(set_proxy(&mut s, false), k3);
 }
+
+/// Marker edits keep the disk key (the sound of a playing preview must not wait for frames to
+/// render again, #1083); an expression that reads markers makes them count.
+#[test]
+fn markers_keep_the_content_key_unless_an_expression_reads_them() {
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"name": "M", "width": 8, "height": 8, "frameRate": 30, "duration": 2})).unwrap();
+    let cid = s.active_comp_id().unwrap();
+    let l = s.execute("layer.newSolid", json!({"color": "#ff0000"})).unwrap()["layer"].as_u64().unwrap();
+    let key = |s: &Session| effectcraft_render::disk_cache::comp_content_key(&s.project, cid);
+    let k0 = key(&s);
+    s.execute("comp.addMarker", json!({"time": 0.5, "comment": "beat"})).unwrap();
+    s.execute("markers.set", json!({"layer": l, "new": true, "time": 0.25})).unwrap();
+    assert_eq!(key(&s), k0, "markers");
+    s.execute("prop.setExpression", json!({"layer": l, "path": "transform/opacity", "expression": "thisComp.marker.numKeys"})).unwrap();
+    let k1 = key(&s);
+    assert_ne!(k1, k0);
+    s.execute("comp.addMarker", json!({"time": 1.0})).unwrap();
+    assert_ne!(key(&s), k1, "a marker read by an expression");
+}
diff --git a/crates/project/src/lib.rs b/crates/project/src/lib.rs
index d7f34b5b8..57824de8c 100644
--- a/crates/project/src/lib.rs
+++ b/crates/project/src/lib.rs
@@ -881,14 +881,30 @@ impl Comp {
     /// The comp with those switches and the Resolution at their defaults (borrowed when they
     /// already are), for keys that hash the whole comp.
     pub fn pixel_form(&self) -> std::borrow::Cow<'_, Comp> {
-        if !self.hide_shy && self.resolution.is_auto() && self.layers.iter().all(|l| l.switches == l.switches.pixels()) {
+        self.pixel_form_with(true)
+    }
+
+    /// [`Self::pixel_form`], also without the comp's and its layers' markers when not
+    /// `with_markers` (see [`Self::same_pixels_with`] and [`Project::reads_markers`]).
+    pub fn pixel_form_with(&self, with_markers: bool) -> std::borrow::Cow<'_, Comp> {
+        if !self.hide_shy
+            && self.resolution.is_auto()
+            && self.layers.iter().all(|l| l.switches == l.switches.pixels())
+            && (with_markers || (self.markers.is_empty() && self.layers.iter().all(|l| l.markers.is_empty())))
+        {
             return std::borrow::Cow::Borrowed(self);
         }
         let mut c = self.clone();
         c.hide_shy = false;
         c.resolution = Resolution::Auto;
+        if !with_markers {
+            c.markers.clear();
+        }
         for l in &mut c.layers {
             l.switches = l.switches.pixels();
+            if !with_markers {
+                l.markers.clear();
+            }
         }
         std::borrow::Cow::Owned(c)
     }
@@ -1339,6 +1355,21 @@ impl Default for Project {
 }
 
 impl Project {
+    /// Some expression mentions markers (`marker.key(1)`, `numKeys`, `nearestKey`...). Only then
+    /// do the markers of comps and layers affect what is rendered, so frame caches ignore them
+    /// otherwise.
+    pub fn reads_markers(&self) -> bool {
+        let mut found = false;
+        for (_, c) in self.comps() {
+            for l in &c.layers {
+                if !found {
+                    l.props.walk("", &mut |_, p| found |= p.expr.as_ref().is_some_and(|e| e.text.to_ascii_lowercase().contains("marker")));
+                }
+            }
+        }
+        found
+    }
+
     /// Allocate an id (items, layers and property uids share one counter).
     pub fn alloc(&mut self) -> u64 {
         let id = self.next_id;
diff --git a/crates/render/src/disk_cache.rs b/crates/render/src/disk_cache.rs
index da46708e7..9c3655f72 100644
--- a/crates/render/src/disk_cache.rs
+++ b/crates/render/src/disk_cache.rs
@@ -780,7 +780,8 @@ pub fn footage_salt(project: &effectcraft_project::Project) -> u64 {
 /// Content key of a composition's pixels: project render settings, the comp and everything it
 /// uses (nested comps, footage, solids, their proxies and Use Proxy switches, footage and proxy
 /// files' size and time). With expressions in play (which can read any comp) the whole project
-/// counts. Switches that don't change pixels (Audio, Lock, Shy, Hide Shy Layers) don't count.
+/// counts. Switches that don't change pixels (Audio, Lock, Shy, Hide Shy Layers) don't count, and
+/// neither do markers unless an expression mentions them.
 pub fn comp_content_key(project: &effectcraft_project::Project, comp: effectcraft_project::ItemId) -> u128 {
     use effectcraft_project::{ItemKind, LayerSource};
     let mut h = Hash128::default();
@@ -805,13 +806,15 @@ pub fn comp_content_key(project: &effectcraft_project::Project, comp: effectcraf
             }
         }
     }
+    // Markers are pixels only to the expressions that read them (#1083).
+    let markers = project.reads_markers();
     let ids: Vec<effectcraft_project::ItemId> = if expressions { project.items.keys().copied().collect() } else { seen.into_iter().collect() };
     for id in ids {
         let Some(it) = project.item(id) else { continue };
         h.write_u64(id.0);
         h.write(it.name.as_bytes());
         match &it.kind {
-            ItemKind::Comp(c) => hash_debug(&mut h, &c.pixel_form()),
+            ItemKind::Comp(c) => hash_debug(&mut h, &c.pixel_form_with(markers)),
             k => hash_debug(&mut h, k),
         }
         if let ItemKind::Footage(f) = &it.kind {
diff --git a/crates/ui-egui/src/frames.rs b/crates/ui-egui/src/frames.rs
index 0923e5eb8..e41a06f7e 100644
--- a/crates/ui-egui/src/frames.rs
+++ b/crates/ui-egui/src/frames.rs
@@ -291,18 +291,6 @@ pub fn comp_content(project: &Project, comp: ItemId) -> u64 {
     comp_content_with(project, comp, |_, c| Arc::as_ptr(c))
 }
 
-/// Some expression in the project mentions markers (`marker.key(1)`, `numKeys`, `nearestKey`…).
-/// Only then do the markers of its comps and layers affect what is rendered.
-fn reads_markers(project: &Project) -> bool {
-    fn group(g: &PropGroup) -> bool {
-        g.children.iter().any(|c| match c {
-            Node::Prop(p) => p.expr.as_ref().is_some_and(|e| e.text.to_ascii_lowercase().contains("marker")),
-            Node::Group(sub) => group(sub),
-        })
-    }
-    project.comps().any(|(_, c)| c.layers.iter().any(|l| group(&l.props)))
-}
-
 /// [`comp_content`] with each comp's address given by `addr`.
 fn comp_content_with(project: &Project, comp: ItemId, addr: impl Fn(ItemId, &Arc<Comp>) -> *const Comp) -> u64 {
     use std::hash::{Hash, Hasher};
@@ -716,7 +704,7 @@ impl Frames {
         let plain = comp_content(project, comp);
         let Ok(mut bases) = self.bases.lock() else { return (plain, None) };
         // Markers are pixels only to the expressions that read them (#1083).
-        let markers = reads_markers(project);
+        let markers = project.reads_markers();
         if let Some((base_id, base)) = bases.get(&comp.0)
             && *base_id != plain
             && comp_content_with(project, comp, |id, c| match base.item(id).map(|i| &i.kind) {