diff --git a/test/fixtures/wpt/README.md b/test/fixtures/wpt/README.md
index 6bcd1e51efd83b..6404571a498200 100644
--- a/test/fixtures/wpt/README.md
+++ b/test/fixtures/wpt/README.md
@@ -31,7 +31,7 @@ Last update:
 - user-timing: https://github.com/web-platform-tests/wpt/tree/5ae85bf826/user-timing
 - wasm/jsapi: https://github.com/web-platform-tests/wpt/tree/cde25e7e3c/wasm/jsapi
 - wasm/webapi: https://github.com/web-platform-tests/wpt/tree/fd1b23eeaa/wasm/webapi
-- WebCryptoAPI: https://github.com/web-platform-tests/wpt/tree/f4e7e32fd0/WebCryptoAPI
+- WebCryptoAPI: https://github.com/web-platform-tests/wpt/tree/d4e14d714c/WebCryptoAPI
 - webidl/ecmascript-binding/es-exceptions: https://github.com/web-platform-tests/wpt/tree/a370aad338/webidl/ecmascript-binding/es-exceptions
 - webmessaging/broadcastchannel: https://github.com/web-platform-tests/wpt/tree/e97fac4791/webmessaging/broadcastchannel
 
diff --git a/test/fixtures/wpt/WebCryptoAPI/import_export/okp_importKey.https.any.js b/test/fixtures/wpt/WebCryptoAPI/import_export/okp_importKey.https.any.js
index a0ec3e81c877e1..a56bd31cbe14b1 100644
--- a/test/fixtures/wpt/WebCryptoAPI/import_export/okp_importKey.https.any.js
+++ b/test/fixtures/wpt/WebCryptoAPI/import_export/okp_importKey.https.any.js
@@ -81,6 +81,11 @@
                     }
 
                     testFormat(format, algorithm, data, vector.name, usages, extractable);
+
+                    // Test for https://github.com/WICG/webcrypto-secure-curves/pull/24
+                    if (format === "jwk" && extractable) {
+                        testJwkAlgBehaviours(algorithm, data.jwk, vector.name, usages);
+                    }
                 });
 
             });
@@ -92,6 +97,11 @@
                     var data = keyData[vector.name];
 
                     testFormat(format, algorithm, data, vector.name, usages, extractable);
+
+                    // Test for https://github.com/WICG/webcrypto-secure-curves/pull/24
+                    if (format === "jwk" && extractable) {
+                        testJwkAlgBehaviours(algorithm, data.jwk, vector.name, usages);
+                    }
                 });
             });
         });
@@ -126,6 +136,28 @@
         }, "Good parameters: " + keySize.toString() + " bits " + parameterString(format, keyData[format], algorithm, extractable, usages));
     }
 
+    // Test importKey/exportKey "alg" behaviours, alg is ignored upon import and alg is missing for Ed25519 and Ed448 JWK export
+    // https://github.com/WICG/webcrypto-secure-curves/pull/24
+    function testJwkAlgBehaviours(algorithm, keyData, crv, usages) {
+        promise_test(function(test) {
+            return subtle.importKey('jwk', { ...keyData, alg: 'this is ignored' }, algorithm, true, usages).
+            then(function(key) {
+                assert_equals(key.constructor, CryptoKey, "Imported a CryptoKey object");
+
+                return subtle.exportKey('jwk', key).
+                then(function(result) {
+                    assert_equals(Object.keys(result).length, keyData.d ? 6 : 5, "Correct number of JWK members");
+                    assert_equals(result.alg, undefined, 'No JWK "alg" member is present');
+                    assert_true(equalJwk(keyData, result), "Round trip works");
+                }, function(err) {
+                    assert_unreached("Threw an unexpected error: " + err.toString());
+                });
+            }, function(err) {
+                assert_unreached("Threw an unexpected error: " + err.toString());
+            });
+        }, "Good parameters with ignored JWK alg: " + crv.toString() + " " + parameterString('jwk', keyData, algorithm, true, usages));
+    }
+
 
 
     // Helper methods follow:
diff --git a/test/fixtures/wpt/WebCryptoAPI/sign_verify/eddsa.js b/test/fixtures/wpt/WebCryptoAPI/sign_verify/eddsa.js
index d425fec2dc343e..d77a8808831176 100644
--- a/test/fixtures/wpt/WebCryptoAPI/sign_verify/eddsa.js
+++ b/test/fixtures/wpt/WebCryptoAPI/sign_verify/eddsa.js
@@ -167,6 +167,7 @@ function run_test() {
           promise_test(function(test) {
               return subtle.sign(algorithm, vector.privateKey, vector.data)
               .then(function(signature) {
+                  assert_true(equalBuffers(signature, vector.signature), "Signing did not give the expected output");
                   // Can we verify the signature?
                   return subtle.verify(algorithm, vector.publicKey, signature, vector.data)
                   .then(function(is_verified) {
diff --git a/test/fixtures/wpt/WebCryptoAPI/sign_verify/hmac.js b/test/fixtures/wpt/WebCryptoAPI/sign_verify/hmac.js
index 8df4b042f54cf6..f5e2ad2769cdd8 100644
--- a/test/fixtures/wpt/WebCryptoAPI/sign_verify/hmac.js
+++ b/test/fixtures/wpt/WebCryptoAPI/sign_verify/hmac.js
@@ -117,6 +117,7 @@ function run_test() {
             promise_test(function(test) {
                 return subtle.sign({name: "HMAC", hash: vector.hash}, vector.key, vector.plaintext)
                 .then(function(signature) {
+                    assert_true(equalBuffers(signature, vector.signature), "Signing did not give the expected output");
                     // Can we get the verify the new signature?
                     return subtle.verify({name: "HMAC", hash: vector.hash}, vector.key, signature, vector.plaintext)
                     .then(function(is_verified) {
diff --git a/test/fixtures/wpt/versions.json b/test/fixtures/wpt/versions.json
index 27daee082506fb..4b28c06e6c40df 100644
--- a/test/fixtures/wpt/versions.json
+++ b/test/fixtures/wpt/versions.json
@@ -84,7 +84,7 @@
     "path": "wasm/webapi"
   },
   "WebCryptoAPI": {
-    "commit": "f4e7e32fd0d4937f5b024602c6bf665ebeb1fa17",
+    "commit": "d4e14d714c5242e174ba9aec43caf5eb514d0f09",
     "path": "WebCryptoAPI"
   },
   "webidl/ecmascript-binding/es-exceptions": {