diff --git a/test/fixtures/wpt/README.md b/test/fixtures/wpt/README.md
index 33af47703674bb..a4ca98dc7ffa4f 100644
--- a/test/fixtures/wpt/README.md
+++ b/test/fixtures/wpt/README.md
@@ -32,7 +32,7 @@ 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/d4e14d714c/WebCryptoAPI
+- WebCryptoAPI: https://github.com/web-platform-tests/wpt/tree/5e042cbc4e/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/derive_bits_keys/cfrg_curves_bits.js b/test/fixtures/wpt/WebCryptoAPI/derive_bits_keys/cfrg_curves_bits.js
index 4e12ca0eb711fa..ef6905e574c158 100644
--- a/test/fixtures/wpt/WebCryptoAPI/derive_bits_keys/cfrg_curves_bits.js
+++ b/test/fixtures/wpt/WebCryptoAPI/derive_bits_keys/cfrg_curves_bits.js
@@ -60,6 +60,15 @@ function define_tests() {
           }, algorithmName + " mixed case parameters");
 
           // Null length
+          // "Null" is not valid per the current spec
+          //   - https://github.com/w3c/webcrypto/issues/322
+          //   - https://github.com/w3c/webcrypto/issues/329
+          //
+          // Proposal for a spec change:
+          //   - https://github.com/w3c/webcrypto/pull/345
+          //
+          // This test case may be replaced by these new tests:
+          //   - https://github.com/web-platform-tests/wpt/pull/43400
           promise_test(function(test) {
               return subtle.deriveBits({name: algorithmName, public: publicKeys[algorithmName]}, privateKeys[algorithmName], null)
               .then(function(derivation) {
diff --git a/test/fixtures/wpt/WebCryptoAPI/derive_bits_keys/ecdh_bits.js b/test/fixtures/wpt/WebCryptoAPI/derive_bits_keys/ecdh_bits.js
index e52ffc6bfdb6f6..cb9747a529fd53 100644
--- a/test/fixtures/wpt/WebCryptoAPI/derive_bits_keys/ecdh_bits.js
+++ b/test/fixtures/wpt/WebCryptoAPI/derive_bits_keys/ecdh_bits.js
@@ -56,6 +56,15 @@ function define_tests() {
             }, namedCurve + " mixed case parameters");
 
             // Null length
+            // "Null" is not valid per the current spec
+            //   - https://github.com/w3c/webcrypto/issues/322
+            //   - https://github.com/w3c/webcrypto/issues/329
+            //
+            // Proposal for a spec change:
+            //   - https://github.com/w3c/webcrypto/pull/345
+            //
+            // This test case may be replaced by these new tests:
+            //   - https://github.com/web-platform-tests/wpt/pull/43400
             promise_test(function(test) {
                 return subtle.deriveBits({name: "ECDH", public: publicKeys[namedCurve]}, privateKeys[namedCurve], null)
                 .then(function(derivation) {
diff --git a/test/fixtures/wpt/WebCryptoAPI/derive_bits_keys/hkdf.js b/test/fixtures/wpt/WebCryptoAPI/derive_bits_keys/hkdf.js
index 2bb58533473eb9..3903da5cddff94 100644
--- a/test/fixtures/wpt/WebCryptoAPI/derive_bits_keys/hkdf.js
+++ b/test/fixtures/wpt/WebCryptoAPI/derive_bits_keys/hkdf.js
@@ -140,6 +140,15 @@ function define_tests() {
                         }, testName + " with missing info");
 
                         // length null (OperationError)
+                        // "Null" is not valid per the current spec
+                        //   - https://github.com/w3c/webcrypto/issues/322
+                        //   - https://github.com/w3c/webcrypto/issues/329
+                        //
+                        // Proposal for a spec change:
+                        //   - https://github.com/w3c/webcrypto/pull/345
+                        //
+                        // This test case may be replaced by these new tests:
+                        //   - https://github.com/web-platform-tests/wpt/pull/43400
                         subsetTest(promise_test, function(test) {
                             return subtle.deriveBits(algorithm, baseKeys[derivedKeySize], null)
                             .then(function(derivation) {
diff --git a/test/fixtures/wpt/WebCryptoAPI/derive_bits_keys/pbkdf2.js b/test/fixtures/wpt/WebCryptoAPI/derive_bits_keys/pbkdf2.js
index 0403f382e1479c..4e4ae79d800a40 100644
--- a/test/fixtures/wpt/WebCryptoAPI/derive_bits_keys/pbkdf2.js
+++ b/test/fixtures/wpt/WebCryptoAPI/derive_bits_keys/pbkdf2.js
@@ -105,6 +105,15 @@ function define_tests() {
 
                         // Test various error conditions for deriveBits below:
                         // length null (OperationError)
+                        // "Null" is not valid per the current spec
+                        //   - https://github.com/w3c/webcrypto/issues/322
+                        //   - https://github.com/w3c/webcrypto/issues/329
+                        //
+                        // Proposal for a spec change:
+                        //   - https://github.com/w3c/webcrypto/pull/345
+                        //
+                        // This test case may be replaced by these new tests:
+                        //   - https://github.com/web-platform-tests/wpt/pull/43400
                         subsetTest(promise_test, function(test) {
                             return subtle.deriveBits({name: "PBKDF2", salt: salts[saltSize], hash: hashName, iterations: parseInt(iterations)}, baseKeys[passwordSize], null)
                             .then(function(derivation) {
diff --git a/test/fixtures/wpt/WebCryptoAPI/import_export/ec_importKey.https.any.js b/test/fixtures/wpt/WebCryptoAPI/import_export/ec_importKey.https.any.js
index 31f062e313f6fe..a01bfbb0ef2e18 100644
--- a/test/fixtures/wpt/WebCryptoAPI/import_export/ec_importKey.https.any.js
+++ b/test/fixtures/wpt/WebCryptoAPI/import_export/ec_importKey.https.any.js
@@ -80,6 +80,9 @@
                         }
 
                         testFormat(format, algorithm, data, curve, usages, extractable);
+                        if (vector.name === 'ECDH' && format === 'jwk') {
+                            testEcdhJwkAlg(algorithm, { ...data.jwk, alg: 'any alg works here' }, curve, usages, extractable);
+                        }
                     });
 
                 });
@@ -90,11 +93,13 @@
                     var data = keyData[curve];
                     allValidUsages(vector.privateUsages).forEach(function(usages) {
                         testFormat(format, algorithm, data, curve, usages, extractable);
+                        if (vector.name === 'ECDH' && format === 'jwk') {
+                            testEcdhJwkAlg(algorithm, { ...data.jwk, alg: 'any alg works here' }, curve, usages, extractable);
+                        }
                     });
                     testEmptyUsages(format, algorithm, data, curve, extractable);
                 });
             });
-
         });
     });
 
@@ -151,6 +156,21 @@
         }, "Empty Usages: " + keySize.toString() + " bits " + parameterString(format, false, keyData, algorithm, extractable, usages));
     }
 
+    // Test ECDH importKey with a JWK format
+    // Should succeed with any "alg" value
+    function testEcdhJwkAlg(algorithm, keyData, keySize, usages, extractable) {
+        const format = "jwk";
+        promise_test(function(test) {
+            return subtle.importKey(format, keyData, algorithm, extractable, usages).
+            then(function(key) {
+                assert_equals(key.constructor, CryptoKey, "Imported a CryptoKey object");
+                assert_goodCryptoKey(key, algorithm, extractable, usages, keyData.d ? 'private' : 'public');
+            }, function(err) {
+                assert_unreached("Threw an unexpected error: " + err.toString());
+            });
+        }, "ECDH any JWK alg: " + keySize.toString() + " bits " + parameterString(format, false, keyData, algorithm, extractable, usages));
+    }
+
 
 
     // Helper methods follow:
diff --git a/test/fixtures/wpt/versions.json b/test/fixtures/wpt/versions.json
index 0e04684b381f2f..a7c655125b5c22 100644
--- a/test/fixtures/wpt/versions.json
+++ b/test/fixtures/wpt/versions.json
@@ -88,7 +88,7 @@
     "path": "wasm/webapi"
   },
   "WebCryptoAPI": {
-    "commit": "d4e14d714c5242e174ba9aec43caf5eb514d0f09",
+    "commit": "5e042cbc4ecab7b2279a5fd411c6daa24ca886c6",
     "path": "WebCryptoAPI"
   },
   "webidl/ecmascript-binding/es-exceptions": {