diff --git a/Cargo.lock b/Cargo.lock
index 6a83cb9f6..ab513baaa 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -451,17 +451,19 @@ checksum = "5b63caa9aa9397e2d9480a9b13673856c78d8ac123288526c37d7839f2a86990"
 [[package]]
 name = "comemo"
 version = "0.4.0"
-source = "git+https://github.com/typst/comemo?rev=60b30c6#60b30c6ae54f3c940dc4f778ca5090bd2a42a72e"
+source = "git+https://github.com/typst/comemo?rev=4b949e2#4b949e2c4f1ac5a6d31c73f06daf290d880ff509"
 dependencies = [
+ "bumpalo",
  "comemo-macros",
  "parking_lot",
  "siphasher",
+ "slab",
 ]
 
 [[package]]
 name = "comemo-macros"
 version = "0.4.0"
-source = "git+https://github.com/typst/comemo?rev=60b30c6#60b30c6ae54f3c940dc4f778ca5090bd2a42a72e"
+source = "git+https://github.com/typst/comemo?rev=4b949e2#4b949e2c4f1ac5a6d31c73f06daf290d880ff509"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2496,6 +2498,12 @@ dependencies = [
  "read-fonts",
 ]
 
+[[package]]
+name = "slab"
+version = "0.4.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "04dc19736151f35336d325007ac991178d504a119863a2fcb3758cdb5e52c50d"
+
 [[package]]
 name = "slotmap"
 version = "1.0.7"
diff --git a/Cargo.toml b/Cargo.toml
index 5e169f295..4c7b9363d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -165,4 +165,4 @@ uninlined_format_args = "warn"
 wildcard_in_or_patterns = "allow"
 
 [patch.crates-io]
-comemo = { git = "https://github.com/typst/comemo", rev = "60b30c6" }
+comemo = { git = "https://github.com/typst/comemo", rev = "4b949e2" }
diff --git a/crates/typst-library/src/engine.rs b/crates/typst-library/src/engine.rs
index cb98f4599..27f03a31f 100644
--- a/crates/typst-library/src/engine.rs
+++ b/crates/typst-library/src/engine.rs
@@ -3,7 +3,7 @@
 use std::collections::HashSet;
 use std::sync::atomic::{AtomicUsize, Ordering};
 
-use comemo::{Track, Tracked, TrackedMut, Validate};
+use comemo::{Track, Tracked, TrackedMut};
 use ecow::EcoVec;
 use rayon::iter::{IndexedParallelIterator, IntoParallelIterator, ParallelIterator};
 use typst_syntax::{FileId, Span};
@@ -219,7 +219,7 @@ pub struct Route<'a> {
     // We need to override the constraint's lifetime here so that `Tracked` is
     // covariant over the constraint. If it becomes invariant, we're in for a
     // world of lifetime pain.
-    outer: Option<Tracked<'a, Self, <Route<'static> as Validate>::Constraint>>,
+    outer: Option<Tracked<'a, Self, <Route<'static> as Track>::Call>>,
     /// This is set if this route segment was inserted through the start of a
     /// module evaluation.
     id: Option<FileId>,
diff --git a/crates/typst-library/src/introspection/locator.rs b/crates/typst-library/src/introspection/locator.rs
index 3ba3d6486..2d07619b9 100644
--- a/crates/typst-library/src/introspection/locator.rs
+++ b/crates/typst-library/src/introspection/locator.rs
@@ -3,7 +3,7 @@ use std::fmt::{self, Debug, Formatter};
 use std::hash::Hash;
 use std::sync::OnceLock;
 
-use comemo::{Tracked, Validate};
+use comemo::{Track, Tracked};
 
 use crate::introspection::{Introspector, Location};
 
@@ -312,7 +312,7 @@ enum LinkKind<'a> {
     /// We need to override the constraint's lifetime here so that `Tracked` is
     /// covariant over the constraint. If it becomes invariant, we're in for a
     /// world of lifetime pain.
-    Outer(Tracked<'a, Locator<'a>, <Locator<'static> as Validate>::Constraint>),
+    Outer(Tracked<'a, Locator<'a>, <Locator<'static> as Track>::Call>),
     /// A link which indicates that we are in measurement mode.
     Measure(Location),
 }
diff --git a/crates/typst/src/lib.rs b/crates/typst/src/lib.rs
index 47e5531fd..7ee8c19a4 100644
--- a/crates/typst/src/lib.rs
+++ b/crates/typst/src/lib.rs
@@ -39,9 +39,9 @@ pub use typst_syntax as syntax;
 pub use typst_utils as utils;
 
 use std::collections::HashSet;
-use std::sync::LazyLock;
+use std::sync::{LazyLock, Mutex};
 
-use comemo::{Track, Tracked, Validate};
+use comemo::{Track, Tracked};
 use ecow::{EcoString, EcoVec, eco_format, eco_vec};
 use typst_html::HtmlDocument;
 use typst_library::diag::{
@@ -135,10 +135,11 @@ fn compile_impl<D: Document>(
 
         subsink = Sink::new();
 
-        let constraint = <Introspector as Validate>::Constraint::new();
+        let constraint = Mutex::new(comemo::Constraint::new());
+        let push = |call, ret| constraint.lock().unwrap().push(call, ret);
         let mut engine = Engine {
             world,
-            introspector: introspector.track_with(&constraint),
+            introspector: introspector.track_with(&push),
             traced,
             sink: subsink.track_mut(),
             route: Route::default(),
@@ -150,7 +151,10 @@ fn compile_impl<D: Document>(
         introspector = document.introspector();
         iter += 1;
 
-        if timed!("check stabilized", introspector.validate(&constraint)) {
+        if timed!(
+            "check stabilized",
+            constraint.into_inner().unwrap().validate(introspector)
+        ) {
             break;
         }