diff --git a/sha1-checked/tests/mod.rs b/sha1-checked/tests/mod.rs
index 72708117..7f09ab45 100644
--- a/sha1-checked/tests/mod.rs
+++ b/sha1-checked/tests/mod.rs
@@ -30,6 +30,7 @@ fn shambles_1() {
         &include_bytes!("./data/sha-mbles-1.bin")[..],
         hex!("8ac60ba76f1999a1ab70223f225aefdc78d4ddc0"),
         hex!("4f3d9be4a472c4dae83c6314aa6c36a064c1fd14"),
+        None,
         false,
     );
 }
@@ -40,6 +41,7 @@ fn shambles_2() {
         &include_bytes!("./data/sha-mbles-2.bin")[..],
         hex!("8ac60ba76f1999a1ab70223f225aefdc78d4ddc0"),
         hex!("9ed5d77a4f48be1dbf3e9e15650733eb850897f2"),
+        None,
         false,
     );
 }
@@ -50,6 +52,7 @@ fn shattered_1() {
         &include_bytes!("./data/shattered-1.pdf")[..],
         hex!("38762cf7f55934b34d179ae6a4c80cadccbb7f0a"),
         hex!("16e96b70000dd1e7c85b8368ee197754400e58ec"),
+        Some(hex!("d3a1d09969c3b57113fd17b23e01dd3de74a99bb")),
         false,
     );
 }
@@ -60,6 +63,7 @@ fn shattered_2() {
         &include_bytes!("./data/shattered-2.pdf")[..],
         hex!("38762cf7f55934b34d179ae6a4c80cadccbb7f0a"),
         hex!("e1761773e6a35916d99f891b77663e6405313587"),
+        Some(hex!("92246b0b718f4c704d37bb025717cbc66babf102")),
         false,
     );
 }
@@ -70,11 +74,18 @@ fn reducedsha_coll() {
         &include_bytes!("./data/sha1_reducedsha_coll.bin")[..],
         hex!("a56374e1cf4c3746499bc7c0acb39498ad2ee185"),
         hex!("dd39885a2a5d8f59030b451e00cb45da9f9d3828"),
+        Some(hex!("dd39885a2a5d8f59030b451e00cb45da9f9d3828")),
         true,
-    )
+    );
 }
 
-fn collision_test(input: &[u8], hash: [u8; 20], mitigated_hash: [u8; 20], reduced_rounds: bool) {
+fn collision_test(
+    input: &[u8],
+    hash: [u8; 20],
+    mitigated_hash: [u8; 20],
+    reduced_rounds_mitigated: Option<[u8; 20]>,
+    reduced_rounds: bool,
+) {
     let has_collision = true;
 
     // No detection.
@@ -114,4 +125,12 @@ fn collision_test(input: &[u8], hash: [u8; 20], mitigated_hash: [u8; 20], reduce
     let d = ctx.try_finalize();
     assert_eq!(d.has_collision(), has_collision);
     assert_eq!(&d.hash()[..], mitigated_hash);
+
+    if let Some(rr) = reduced_rounds_mitigated {
+        let mut ctx = Sha1::builder().reduced_round_collision(true).build();
+        ctx.update(input);
+        let d = ctx.try_finalize();
+        assert_eq!(d.has_collision(), has_collision);
+        assert_eq!(&d.hash()[..], rr);
+    }
 }