diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 98c77507..efcb2066 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -48,6 +48,11 @@ jobs:
       - uses: dtolnay/rust-toolchain@master
         with:
           toolchain: ${{ matrix.rust }}
+      - name: Downgrade dependencies
+        if: matrix.rust == '1.63.0'
+        run: |
+          cargo generate-lockfile
+          cargo update -p hashbrown --precise 0.15.0
       - name: Tests
         run: |
           cargo build --verbose --features "${{ matrix.features }}"
@@ -83,6 +88,11 @@ jobs:
         with:
           toolchain: ${{ matrix.rust }}
           target: ${{ matrix.target }}
+      - name: Downgrade dependencies
+        if: matrix.rust == '1.63.0'
+        run: |
+          cargo generate-lockfile
+          cargo update -p hashbrown --precise 0.15.0
       - name: Tests
         run: |
           cargo build -vv --target=${{ matrix.target }} --no-default-features
diff --git a/Cargo.toml b/Cargo.toml
index 959ea4c6..9e22c312 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -20,7 +20,7 @@ arbitrary = { version = "1.0", optional = true, default-features = false }
 quickcheck = { version = "1.0", optional = true, default-features = false }
 serde = { version = "1.0", optional = true, default-features = false }
 borsh = { version = "1.2", optional = true, default-features = false }
-rayon = { version = "1.5.3", optional = true }
+rayon = { version = "1.9", optional = true }
 
 # Internal feature, only used when building as part of rustc,
 # not part of the stable interface of this crate.
diff --git a/src/rayon/mod.rs b/src/rayon/mod.rs
index 1d21569c..84ce02db 100644
--- a/src/rayon/mod.rs
+++ b/src/rayon/mod.rs
@@ -12,18 +12,5 @@ pub mod set;
 // This form of intermediate collection is also how Rayon collects `HashMap`.
 // Note that the order will also be preserved!
 fn collect<I: IntoParallelIterator>(iter: I) -> LinkedList<Vec<I::Item>> {
-    iter.into_par_iter()
-        .fold(Vec::new, |mut vec, elem| {
-            vec.push(elem);
-            vec
-        })
-        .map(|vec| {
-            let mut list = LinkedList::new();
-            list.push_back(vec);
-            list
-        })
-        .reduce(LinkedList::new, |mut list1, mut list2| {
-            list1.append(&mut list2);
-            list1
-        })
+    iter.into_par_iter().collect_vec_list()
 }