diff --git a/.github/workflows/Tests.yml b/.github/workflows/Tests.yml
index 853ea1c..5ceb863 100644
--- a/.github/workflows/Tests.yml
+++ b/.github/workflows/Tests.yml
@@ -26,9 +26,11 @@ jobs:
         uses: actions/checkout@v2
       - name: Install Rust
         run: |
-          rustup toolchain install nightly-2021-01-19
-          rustup default nightly-2021-01-19
-          rustup component add rustfmt miri
+          MIRI_NIGHTLY=nightly-$(curl -s https://rust-lang.github.io/rustup-components-history/x86_64-unknown-linux-gnu/miri)
+          echo "Installing latest nightly with Miri: $MIRI_NIGHTLY"
+          rustup set profile minimal
+          rustup default "$MIRI_NIGHTLY"
+          rustup component add miri
       - name: Run
         run: |
           make miri
diff --git a/Makefile b/Makefile
index 44ec1c7..0974346 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,6 @@
 test:
 	cargo test -- --nocapture
+	cargo test -- --ignored -- --nocapture
 
 miri:
 	cargo miri test -- --nocapture
diff --git a/src/lib.rs b/src/lib.rs
index ebf2adb..9814c3d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -286,6 +286,22 @@ mod tests {
     /// verifies the result against std's `sort`.
     #[test]
     fn sorted_random_u64_test() {
+        let mut rng = rand::thread_rng();
+        let vec_size = 1025;
+        let partial_size = (rng.gen::<u64>() % vec_size) as usize;
+        let mut data = (0u64..vec_size)
+            .map(|_| rng.gen::<u64>())
+            .collect::<Vec<u64>>();
+        let mut d = data.clone();
+        d.sort();
+
+        data.partial_sort(partial_size, |a, b| a.cmp(b));
+        assert_eq!(&d[0..partial_size], &data.as_slice()[0..partial_size]);
+    }
+
+    #[test]
+    #[ignore]
+    fn sorted_expensive_random_u64_test() {
         for _ in 0..100 {
             let mut rng = rand::thread_rng();
             let vec_size = 1025;