diff --git a/lib/std/crypto/hkdf.zig b/lib/std/crypto/hkdf.zig
index 9163ba9d15..d8270f984c 100644
--- a/lib/std/crypto/hkdf.zig
+++ b/lib/std/crypto/hkdf.zig
@@ -88,3 +88,12 @@ test "Hkdf" {
     hkdf.final(&prk2);
     try htest.assertEqual("077709362c2e32df0ddc3f0dc47bba6390b6c73bb50f9c3122ec844ad7c2b3e5", &prk2);
 }
+
+test "Hkdf Sha3-512" {
+    const sha3_512 = std.crypto.hash.sha3.Sha3_512;
+    const hmac_sha3_512 = hmac.Hmac(sha3_512);
+    const hkdf = Hkdf(hmac_sha3_512);
+    const prk = hkdf.extract("", "");
+    var out = [1]u8{0};
+    hkdf.expand(out[0..], "", prk);
+}
diff --git a/lib/std/crypto/sha3.zig b/lib/std/crypto/sha3.zig
index 4ea09e0f93..a001538c1d 100644
--- a/lib/std/crypto/sha3.zig
+++ b/lib/std/crypto/sha3.zig
@@ -52,7 +52,7 @@ pub fn Keccak(comptime f: u11, comptime output_bits: u11, comptime default_delim
         st: State,
 
         /// The output length, in bytes.
-        pub const digest_length = output_bits / 8;
+        pub const digest_length = std.math.divCeil(comptime_int, output_bits, 8) catch unreachable;
         /// The block length, or rate, in bytes.
         pub const block_length = State.rate;
         /// The delimiter can be overwritten in the options.