diff --git a/Cargo.lock b/Cargo.lock
index 562456fece0..7a7c5f5debc 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4221,9 +4221,9 @@ dependencies = [
 
 [[package]]
 name = "rayon_croissant"
-version = "0.1.1"
+version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5b725e815f3aa08718063883a75003336889debafe2f8fa67fbe91563ddc4efa"
+checksum = "3e4aafda434bd10fec689858e2b1d713d0b784b1e60df3761ac8fa727d7e8e27"
 dependencies = [
  "moite_moite",
  "rayon",
diff --git a/components/layout_2020/Cargo.toml b/components/layout_2020/Cargo.toml
index 5a28da8d9ee..1d76d00af79 100644
--- a/components/layout_2020/Cargo.toml
+++ b/components/layout_2020/Cargo.toml
@@ -25,7 +25,7 @@ msg = {path = "../msg"}
 net_traits = {path = "../net_traits"}
 range = {path = "../range"}
 rayon = "1"
-rayon_croissant = "0.1.1"
+rayon_croissant = "0.2.0"
 script_layout_interface = {path = "../script_layout_interface"}
 script_traits = {path = "../script_traits"}
 serde = "1.0"
diff --git a/components/layout_2020/flow/construct.rs b/components/layout_2020/flow/construct.rs
index 4a397add2c3..25b401e5592 100644
--- a/components/layout_2020/flow/construct.rs
+++ b/components/layout_2020/flow/construct.rs
@@ -172,14 +172,6 @@ impl BlockContainer {
             contains_floats: ContainsFloats,
             outer_content_sizes_of_children: ContentSizes,
         }
-        impl Default for Accumulator {
-            fn default() -> Self {
-                Self {
-                    contains_floats: ContainsFloats::No,
-                    outer_content_sizes_of_children: ContentSizes::zero(),
-                }
-            }
-        }
         let mut acc = Accumulator {
             contains_floats: builder.contains_floats,
             outer_content_sizes_of_children: ContentSizes::zero(),
@@ -199,13 +191,21 @@ impl BlockContainer {
             builder
                 .block_level_boxes
                 .into_par_iter()
-                .mapfold_reduce_into(&mut acc, mapfold, |left, right| {
-                    left.contains_floats |= right.contains_floats;
-                    if content_sizes.requests_inline() {
-                        left.outer_content_sizes_of_children
-                            .max_assign(&right.outer_content_sizes_of_children)
-                    }
-                })
+                .mapfold_reduce_into(
+                    &mut acc,
+                    mapfold,
+                    || Accumulator {
+                        contains_floats: ContainsFloats::No,
+                        outer_content_sizes_of_children: ContentSizes::zero(),
+                    },
+                    |left, right| {
+                        left.contains_floats |= right.contains_floats;
+                        if content_sizes.requests_inline() {
+                            left.outer_content_sizes_of_children
+                                .max_assign(&right.outer_content_sizes_of_children)
+                        }
+                    },
+                )
                 .collect()
         } else {
             builder
diff --git a/components/layout_2020/flow/mod.rs b/components/layout_2020/flow/mod.rs
index 3c1df828d1f..449789530e6 100644
--- a/components/layout_2020/flow/mod.rs
+++ b/components/layout_2020/flow/mod.rs
@@ -235,6 +235,7 @@ fn layout_block_level_children<'a>(
                             /* float_context = */ None,
                         )
                     },
+                    Default::default,
                     |left, right| left.append(right),
                 )
                 .collect();