diff --git a/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSRuntime.cs b/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSRuntime.cs
index e65fb3e9c20f..5a72fe8275d0 100644
--- a/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSRuntime.cs
+++ b/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSRuntime.cs
@@ -23,7 +23,7 @@ protected WebAssemblyJSRuntime()
     }
 
     /// <inheritdoc />
-    protected override string InvokeJS(string identifier, string? argsJson, JSCallResultType resultType, long targetInstanceId)
+    protected override string InvokeJS(string identifier, [StringSyntax(StringSyntaxAttribute.Json)] string? argsJson, JSCallResultType resultType, long targetInstanceId)
     {
         var callInfo = new JSCallInfo
         {
@@ -42,7 +42,7 @@ protected override string InvokeJS(string identifier, string? argsJson, JSCallRe
     }
 
     /// <inheritdoc />
-    protected override void BeginInvokeJS(long asyncHandle, string identifier, string? argsJson, JSCallResultType resultType, long targetInstanceId)
+    protected override void BeginInvokeJS(long asyncHandle, string identifier, [StringSyntax(StringSyntaxAttribute.Json)] string? argsJson, JSCallResultType resultType, long targetInstanceId)
     {
         var callInfo = new JSCallInfo
         {
diff --git a/src/JSInterop/Microsoft.JSInterop/src/Infrastructure/DotNetDispatcher.cs b/src/JSInterop/Microsoft.JSInterop/src/Infrastructure/DotNetDispatcher.cs
index 38e84716e17e..5640fce75a5f 100644
--- a/src/JSInterop/Microsoft.JSInterop/src/Infrastructure/DotNetDispatcher.cs
+++ b/src/JSInterop/Microsoft.JSInterop/src/Infrastructure/DotNetDispatcher.cs
@@ -42,7 +42,7 @@ public static class DotNetDispatcher
     /// <param name="argsJson">A JSON representation of the parameters.</param>
     /// <returns>A JSON representation of the return value, or null.</returns>
     [UnconditionalSuppressMessage("Trimming", "IL2026", Justification = "We expect application code is configured to ensure return types of JSInvokable methods are retained.")]
-    public static string? Invoke(JSRuntime jsRuntime, in DotNetInvocationInfo invocationInfo, string argsJson)
+    public static string? Invoke(JSRuntime jsRuntime, in DotNetInvocationInfo invocationInfo, [StringSyntax(StringSyntaxAttribute.Json)] string argsJson)
     {
         // This method doesn't need [JSInvokable] because the platform is responsible for having
         // some way to dispatch calls here. The logic inside here is the thing that checks whether
@@ -72,7 +72,7 @@ public static class DotNetDispatcher
     /// <param name="argsJson">A JSON representation of the parameters.</param>
     /// <returns>A JSON representation of the return value, or null.</returns>
     [UnconditionalSuppressMessage("Trimming", "IL2026", Justification = "We expect application code is configured to ensure return types of JSInvokable methods are retained.")]
-    public static void BeginInvokeDotNet(JSRuntime jsRuntime, DotNetInvocationInfo invocationInfo, string argsJson)
+    public static void BeginInvokeDotNet(JSRuntime jsRuntime, DotNetInvocationInfo invocationInfo, [StringSyntax(StringSyntaxAttribute.Json)] string argsJson)
     {
         // This method doesn't need [JSInvokable] because the platform is responsible for having
         // some way to dispatch calls here. The logic inside here is the thing that checks whether
diff --git a/src/JSInterop/Microsoft.JSInterop/src/JSInProcessRuntime.cs b/src/JSInterop/Microsoft.JSInterop/src/JSInProcessRuntime.cs
index d9810b89cd5c..4092349c3882 100644
--- a/src/JSInterop/Microsoft.JSInterop/src/JSInProcessRuntime.cs
+++ b/src/JSInterop/Microsoft.JSInterop/src/JSInProcessRuntime.cs
@@ -51,7 +51,7 @@ public abstract class JSInProcessRuntime : JSRuntime, IJSInProcessRuntime
     /// <param name="identifier">The identifier for the function to invoke.</param>
     /// <param name="argsJson">A JSON representation of the arguments.</param>
     /// <returns>A JSON representation of the result.</returns>
-    protected virtual string? InvokeJS(string identifier, string? argsJson)
+    protected virtual string? InvokeJS(string identifier, [StringSyntax(StringSyntaxAttribute.Json)] string? argsJson)
         => InvokeJS(identifier, argsJson, JSCallResultType.Default, 0);
 
     /// <summary>
@@ -62,5 +62,5 @@ public abstract class JSInProcessRuntime : JSRuntime, IJSInProcessRuntime
     /// <param name="resultType">The type of result expected from the invocation.</param>
     /// <param name="targetInstanceId">The instance ID of the target JS object.</param>
     /// <returns>A JSON representation of the result.</returns>
-    protected abstract string? InvokeJS(string identifier, string? argsJson, JSCallResultType resultType, long targetInstanceId);
+    protected abstract string? InvokeJS(string identifier, [StringSyntax(StringSyntaxAttribute.Json)] string? argsJson, JSCallResultType resultType, long targetInstanceId);
 }
diff --git a/src/JSInterop/Microsoft.JSInterop/src/JSRuntime.cs b/src/JSInterop/Microsoft.JSInterop/src/JSRuntime.cs
index 59cc9153d72a..d406ed1e6f15 100644
--- a/src/JSInterop/Microsoft.JSInterop/src/JSRuntime.cs
+++ b/src/JSInterop/Microsoft.JSInterop/src/JSRuntime.cs
@@ -154,7 +154,7 @@ private void CleanupTasksAndRegistrations(long taskId)
     /// <param name="taskId">The identifier for the function invocation, or zero if no async callback is required.</param>
     /// <param name="identifier">The identifier for the function to invoke.</param>
     /// <param name="argsJson">A JSON representation of the arguments.</param>
-    protected virtual void BeginInvokeJS(long taskId, string identifier, string? argsJson)
+    protected virtual void BeginInvokeJS(long taskId, string identifier, [StringSyntax(StringSyntaxAttribute.Json)] string? argsJson)
         => BeginInvokeJS(taskId, identifier, argsJson, JSCallResultType.Default, 0);
 
     /// <summary>
@@ -165,7 +165,7 @@ protected virtual void BeginInvokeJS(long taskId, string identifier, string? arg
     /// <param name="argsJson">A JSON representation of the arguments.</param>
     /// <param name="resultType">The type of result expected from the invocation.</param>
     /// <param name="targetInstanceId">The instance ID of the target JS object.</param>
-    protected abstract void BeginInvokeJS(long taskId, string identifier, string? argsJson, JSCallResultType resultType, long targetInstanceId);
+    protected abstract void BeginInvokeJS(long taskId, string identifier, [StringSyntax(StringSyntaxAttribute.Json)] string? argsJson, JSCallResultType resultType, long targetInstanceId);
 
     /// <summary>
     /// Completes an async JS interop call from JavaScript to .NET