diff --git a/cli/tests/unit/webcrypto_test.ts b/cli/tests/unit/webcrypto_test.ts
index 0e7e2829a0..c942e36c6b 100644
--- a/cli/tests/unit/webcrypto_test.ts
+++ b/cli/tests/unit/webcrypto_test.ts
@@ -1443,7 +1443,7 @@ Deno.test(async function testAesGcmEncrypt() {
   const data = new Uint8Array([1, 2, 3]);
 
   const cipherText = await crypto.subtle.encrypt(
-    { name: "AES-GCM", iv, additionalData: new Uint8Array() },
+    { name: "AES-GCM", iv },
     key,
     data,
   );
@@ -1457,7 +1457,7 @@ Deno.test(async function testAesGcmEncrypt() {
   );
 
   const plainText = await crypto.subtle.decrypt(
-    { name: "AES-GCM", iv, additionalData: new Uint8Array() },
+    { name: "AES-GCM", iv },
     key,
     cipherText,
   );
@@ -1655,14 +1655,14 @@ Deno.test(async function testAesGcmTagLength() {
   // encrypt won't fail, it will simply truncate the tag
   // as expected.
   const encrypted = await crypto.subtle.encrypt(
-    { name: "AES-GCM", iv, tagLength: 96, additionalData: new Uint8Array() },
+    { name: "AES-GCM", iv, tagLength: 96 },
     key,
     new Uint8Array(32),
   );
 
   await assertRejects(async () => {
     await crypto.subtle.decrypt(
-      { name: "AES-GCM", iv, tagLength: 96, additionalData: new Uint8Array() },
+      { name: "AES-GCM", iv, tagLength: 96 },
       key,
       encrypted,
     );
diff --git a/ext/crypto/00_crypto.js b/ext/crypto/00_crypto.js
index 0bde30c5f2..8203a53070 100644
--- a/ext/crypto/00_crypto.js
+++ b/ext/crypto/00_crypto.js
@@ -691,7 +691,8 @@
             algorithm: "AES-GCM",
             length: key[_algorithm].length,
             iv: normalizedAlgorithm.iv,
-            additionalData: normalizedAlgorithm.additionalData,
+            additionalData: normalizedAlgorithm.additionalData ||
+              null,
             tagLength: normalizedAlgorithm.tagLength,
           }, data);
 
@@ -3825,7 +3826,7 @@
           algorithm: "AES-GCM",
           length: key[_algorithm].length,
           iv: normalizedAlgorithm.iv,
-          additionalData: normalizedAlgorithm.additionalData,
+          additionalData: normalizedAlgorithm.additionalData || null,
           tagLength: normalizedAlgorithm.tagLength,
         }, data);