diff --git a/blake2/src/impl_hacl.rs b/blake2/src/impl_hacl.rs
index 5f8e6d98a..70f8160d2 100644
--- a/blake2/src/impl_hacl.rs
+++ b/blake2/src/impl_hacl.rs
@@ -324,10 +324,12 @@ impl<const OUT_LEN: usize> Blake2s<0, OUT_LEN> {
 
 #[cfg(test)]
 mod test {
+    use crate::{Blake2s, Blake2sBuilder};
+
     use super::{Blake2b, Blake2bBuilder};
 
     #[test]
-    fn test_hash() {
+    fn test_blake2b() {
         let mut got_hash = [0; 32];
         let mut hasher: Blake2b<0, 32> = Blake2bBuilder::new().unwrap().build();
         hasher.update(b"this is a test").unwrap();
@@ -336,6 +338,14 @@ mod test {
 
         assert_eq!(&got_hash, expected_hash);
 
+        let mut got_hash = [0; 32];
+        let mut hasher: Blake2b<4, 32> = Blake2bBuilder::new().unwrap().with_key(b"test").build();
+        hasher.update(b"this is a test").unwrap();
+        hasher.finalize(&mut got_hash);
+        let expected_hash = b"\x2a\xbb\x86\x16\xc6\x99\xe5\x1d\xa3\x65\xca\xb7\xad\xe0\x53\x92\xaf\xa2\xc3\xc6\x13\x08\x7f\x84\xb0\xd1\x6e\x5a\x4f\xab\xa7\xb8";
+
+        assert_eq!(&got_hash, expected_hash);
+
         let mut got_hash = [0; 64];
         let mut hasher: Blake2b<0, 64> = Blake2bBuilder::new().unwrap().build();
         hasher.update(b"this is a test").unwrap();
@@ -344,4 +354,23 @@ mod test {
 
         assert_eq!(&got_hash, expected_hash);
     }
+
+    #[test]
+    fn test_blake2s() {
+        let mut got_hash = [0; 32];
+
+        let mut hasher: Blake2s<0, 32> = Blake2sBuilder::new().unwrap().build();
+        hasher.update(b"this is a test").unwrap();
+        hasher.finalize(&mut got_hash);
+        let expected_hash = b"\xf2\x01\x46\xc0\x54\xf9\xdd\x6b\x67\x64\xb6\xc0\x93\x57\xf7\xcd\x75\x51\xdf\xbc\xba\x54\x59\x72\xa4\xc8\x16\x6d\xf8\xaf\xde\x60";
+
+        assert_eq!(&got_hash, expected_hash);
+
+        let mut hasher: Blake2s<4, 32> = Blake2sBuilder::new().unwrap().with_key(b"test").build();
+        hasher.update(b"this is a test").unwrap();
+        hasher.finalize(&mut got_hash);
+        let expected_hash = b"\x98\xfb\xfa\x89\xb3\xee\x07\x51\x9e\xe6\x2c\x18\xfe\x9d\x85\xdc\xf0\x83\x7b\x12\xae\x4d\xe7\x29\xf0\x7b\x55\xa9\x1a\x94\x80\xe8";
+
+        assert_eq!(&got_hash, expected_hash);
+    }
 }