diff --git a/src/index.test.ts b/src/index.test.ts
index 9e36ce70..08a0d657 100644
--- a/src/index.test.ts
+++ b/src/index.test.ts
@@ -41,6 +41,7 @@ describe('index', () => {
         "KnownCaipNamespace",
         "PendingJsonRpcResponseStruct",
         "StrictHexStruct",
+        "UnsafeFastJsonStruct",
         "UnsafeJsonStruct",
         "VersionRangeStruct",
         "VersionStruct",
diff --git a/src/json.test.ts b/src/json.test.ts
index ccd823e4..c4e620a5 100644
--- a/src/json.test.ts
+++ b/src/json.test.ts
@@ -236,7 +236,7 @@ describe('json', () => {
       const [error] = validate(undefined, JsonStruct);
       assert(error !== undefined);
       expect(error.message).toBe(
-        'Expected the value to satisfy a union of `literal | boolean | finite number | string | array | record`, but received: undefined',
+        'Expected a value of type `JSON`, but received: `undefined`',
       );
     });
   });
@@ -432,11 +432,7 @@ describe('json', () => {
           },
         },
       };
-      const now = performance.now();
-      expect(() =>
-        assertIsJsonRpcRequest(request),
-      ).not.toThrow();
-      console.log('Asserting took', performance.now() - now);
+      expect(() => assertIsJsonRpcRequest(request)).not.toThrow();
     });
   });
 
diff --git a/src/json.ts b/src/json.ts
index f01a44c0..f8b75eb6 100644
--- a/src/json.ts
+++ b/src/json.ts
@@ -182,14 +182,28 @@ function validateJson(json: unknown): boolean {
   }
 
   if (typeof json === 'object') {
+    let every = true;
     if (Array.isArray(json)) {
-      return json.every((value) => validateJson(value));
+      // eslint-disable-next-line @typescript-eslint/prefer-for-of
+      for (let i = 0; i < json.length; i++) {
+        if (!validateJson(json[i])) {
+          every = false;
+          break;
+        }
+      }
+      return every;
     }
 
     const entries = Object.entries(json);
-    return entries.every(
-      ([key, value]) => typeof key === 'string' && validateJson(value),
-    );
+    // eslint-disable-next-line @typescript-eslint/prefer-for-of
+    for (let i = 0; i < entries.length; i++) {
+      // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+      if (typeof entries[i]![0] !== 'string' || !validateJson(entries[i]![1])) {
+        every = false;
+        break;
+      }
+    }
+    return every;
   }
 
   return false;
@@ -197,7 +211,7 @@ function validateJson(json: unknown): boolean {
 
 /**
  * A struct to check if the given value is a valid JSON-serializable value.
- * 
+ *
  * A faster alternative to {@link UnsafeJsonStruct}.
  *
  * Note that this struct is unsafe. For safe validation, use {@link JsonStruct}.
diff --git a/src/node.test.ts b/src/node.test.ts
index 5f7d5ed4..b0cada9b 100644
--- a/src/node.test.ts
+++ b/src/node.test.ts
@@ -41,6 +41,7 @@ describe('node', () => {
         "KnownCaipNamespace",
         "PendingJsonRpcResponseStruct",
         "StrictHexStruct",
+        "UnsafeFastJsonStruct",
         "UnsafeJsonStruct",
         "VersionRangeStruct",
         "VersionStruct",