diff --git a/samples/StandaloneApp/Shared/MainLayout.cshtml b/samples/StandaloneApp/Shared/MainLayout.cshtml
index 985a2ec2e6..7202cfb4a7 100644
--- a/samples/StandaloneApp/Shared/MainLayout.cshtml
+++ b/samples/StandaloneApp/Shared/MainLayout.cshtml
@@ -15,5 +15,6 @@
 </div>
 
 @functions {
+    [Parameter]
     public RenderFragment Body { get; set; }
 }
diff --git a/src/Microsoft.AspNetCore.Blazor.Razor.Extensions/BlazorApi.cs b/src/Microsoft.AspNetCore.Blazor.Razor.Extensions/BlazorApi.cs
index 581c3f6cda..8961ea5791 100644
--- a/src/Microsoft.AspNetCore.Blazor.Razor.Extensions/BlazorApi.cs
+++ b/src/Microsoft.AspNetCore.Blazor.Razor.Extensions/BlazorApi.cs
@@ -16,6 +16,11 @@ namespace Microsoft.AspNetCore.Blazor.Razor
             public static readonly string BuildRenderTree = nameof(BuildRenderTree);
         }
 
+        public static class ParameterAttribute
+        {
+            public static readonly string FullTypeName = "Microsoft.AspNetCore.Blazor.Components.ParameterAttribute";
+        }
+
         public static class LayoutAttribute
         {
             public static readonly string FullTypeName = "Microsoft.AspNetCore.Blazor.Layouts.LayoutAttribute";
diff --git a/src/Microsoft.AspNetCore.Blazor.Razor.Extensions/ComponentTagHelperDescriptorProvider.cs b/src/Microsoft.AspNetCore.Blazor.Razor.Extensions/ComponentTagHelperDescriptorProvider.cs
index 9ba01f12e6..79df0b3840 100644
--- a/src/Microsoft.AspNetCore.Blazor.Razor.Extensions/ComponentTagHelperDescriptorProvider.cs
+++ b/src/Microsoft.AspNetCore.Blazor.Razor.Extensions/ComponentTagHelperDescriptorProvider.cs
@@ -42,6 +42,13 @@ namespace Microsoft.AspNetCore.Blazor.Razor
                 return;
             }
 
+            var parameterSymbol = compilation.GetTypeByMetadataName(BlazorApi.ParameterAttribute.FullTypeName);
+            if (parameterSymbol == null)
+            {
+                // No definition for [Parameter], nothing to do.
+                return;
+            }
+
             var types = new List<INamedTypeSymbol>();
             var visitor = new ComponentTypeVisitor(componentSymbol, types);
 
@@ -60,17 +67,22 @@ namespace Microsoft.AspNetCore.Blazor.Razor
             for (var i = 0; i < types.Count; i++)
             {
                 var type = types[i];
-                context.Results.Add(CreateDescriptor(type));
+                context.Results.Add(CreateDescriptor(type, parameterSymbol));
             }
         }
 
-        private TagHelperDescriptor CreateDescriptor(INamedTypeSymbol type)
+        private TagHelperDescriptor CreateDescriptor(INamedTypeSymbol type, INamedTypeSymbol parameterSymbol)
         {
             if (type == null)
             {
                 throw new ArgumentNullException(nameof(type));
             }
 
+            if (parameterSymbol == null)
+            {
+                throw new ArgumentNullException(nameof(parameterSymbol));
+            }
+
             var typeName = type.ToDisplayString(FullNameTypeDisplayFormat);
             var assemblyName = type.ContainingAssembly.Identity.Name;
 
@@ -90,7 +102,7 @@ namespace Microsoft.AspNetCore.Blazor.Razor
             // Components have very simple matching rules. The type name (short) matches the tag name.
             builder.TagMatchingRule(r => r.TagName = type.Name);
 
-            foreach (var property in GetVisibleProperties(type))
+            foreach (var property in GetProperties(type, parameterSymbol))
             {
                 if (property.kind == PropertyKind.Ignored)
                 {
@@ -134,7 +146,7 @@ namespace Microsoft.AspNetCore.Blazor.Razor
         // - has public getter
         // - has public setter
         // - is not an indexer
-        private IEnumerable<(IPropertySymbol property, PropertyKind kind)> GetVisibleProperties(INamedTypeSymbol type)
+        private IEnumerable<(IPropertySymbol property, PropertyKind kind)> GetProperties(INamedTypeSymbol type, INamedTypeSymbol parameterSymbol)
         {
             var properties = new Dictionary<string, (IPropertySymbol, PropertyKind)>(StringComparer.Ordinal);
             do
@@ -174,6 +186,12 @@ namespace Microsoft.AspNetCore.Blazor.Razor
                         kind = PropertyKind.Ignored;
                     }
 
+                    if (!property.GetAttributes().Any(a => a.AttributeClass == parameterSymbol))
+                    {
+                        // Does not have [Parameter]
+                        kind = PropertyKind.Ignored;
+                    }
+
                     if (kind == PropertyKind.Default && property.Type.TypeKind == TypeKind.Enum)
                     {
                         kind = PropertyKind.Enum;
diff --git a/src/Microsoft.AspNetCore.Blazor.Templates/content/BlazorHosted.CSharp/BlazorHosted.CSharp.Client/Shared/SurveyPrompt.cshtml b/src/Microsoft.AspNetCore.Blazor.Templates/content/BlazorHosted.CSharp/BlazorHosted.CSharp.Client/Shared/SurveyPrompt.cshtml
index 740ae82400..f1f7ffebac 100644
--- a/src/Microsoft.AspNetCore.Blazor.Templates/content/BlazorHosted.CSharp/BlazorHosted.CSharp.Client/Shared/SurveyPrompt.cshtml
+++ b/src/Microsoft.AspNetCore.Blazor.Templates/content/BlazorHosted.CSharp/BlazorHosted.CSharp.Client/Shared/SurveyPrompt.cshtml
@@ -14,5 +14,6 @@
 @functions
 {
     // This is to demonstrate how a parent component can supply parameters
+    [Parameter]
     public string Title { get; set; }
 }
diff --git a/src/Microsoft.AspNetCore.Blazor.Templates/content/BlazorStandalone.CSharp/Shared/SurveyPrompt.cshtml b/src/Microsoft.AspNetCore.Blazor.Templates/content/BlazorStandalone.CSharp/Shared/SurveyPrompt.cshtml
index 740ae82400..f1f7ffebac 100644
--- a/src/Microsoft.AspNetCore.Blazor.Templates/content/BlazorStandalone.CSharp/Shared/SurveyPrompt.cshtml
+++ b/src/Microsoft.AspNetCore.Blazor.Templates/content/BlazorStandalone.CSharp/Shared/SurveyPrompt.cshtml
@@ -14,5 +14,6 @@
 @functions
 {
     // This is to demonstrate how a parent component can supply parameters
+    [Parameter]
     public string Title { get; set; }
 }
diff --git a/src/Microsoft.AspNetCore.Blazor/Components/ParameterAttribute.cs b/src/Microsoft.AspNetCore.Blazor/Components/ParameterAttribute.cs
new file mode 100644
index 0000000000..c92f41fbd6
--- /dev/null
+++ b/src/Microsoft.AspNetCore.Blazor/Components/ParameterAttribute.cs
@@ -0,0 +1,15 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+
+namespace Microsoft.AspNetCore.Blazor.Components
+{
+    /// <summary>
+    /// Denotes the target member as a component parameter.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = false)]
+    public sealed class ParameterAttribute : Attribute
+    {
+    }
+}
diff --git a/src/Microsoft.AspNetCore.Blazor/Components/ParameterCollectionExtensions.cs b/src/Microsoft.AspNetCore.Blazor/Components/ParameterCollectionExtensions.cs
index 1f39d7df85..9ef5a2ea1d 100644
--- a/src/Microsoft.AspNetCore.Blazor/Components/ParameterCollectionExtensions.cs
+++ b/src/Microsoft.AspNetCore.Blazor/Components/ParameterCollectionExtensions.cs
@@ -66,6 +66,13 @@ namespace Microsoft.AspNetCore.Blazor.Components
                     $"matching the name '{propertyName}'.");
             }
 
+            if (!property.IsDefined(typeof(ParameterAttribute)))
+            {
+                throw new InvalidOperationException(
+                    $"Object of type '{targetType.FullName}' has a property matching the name '{propertyName}', " +
+                    $"but it does not have [{nameof(ParameterAttribute)}] applied.");
+            }
+
             return property;
         }
     }
diff --git a/src/Microsoft.AspNetCore.Blazor/Layouts/LayoutDisplay.cs b/src/Microsoft.AspNetCore.Blazor/Layouts/LayoutDisplay.cs
index dab3c7fba1..a7a938ba74 100644
--- a/src/Microsoft.AspNetCore.Blazor/Layouts/LayoutDisplay.cs
+++ b/src/Microsoft.AspNetCore.Blazor/Layouts/LayoutDisplay.cs
@@ -21,11 +21,13 @@ namespace Microsoft.AspNetCore.Blazor.Layouts
         /// Gets or sets the type of the page component to display.
         /// The type must implement <see cref="IComponent"/>.
         /// </summary>
+        [Parameter]
         public Type Page { get; set; }
 
         /// <summary>
         /// Gets or sets the parameters to pass to the page.
         /// </summary>
+        [Parameter]
         public IDictionary<string, object> PageParameters { get; set; }
 
         /// <inheritdoc />
diff --git a/src/Microsoft.AspNetCore.Blazor/Routing/NavLink.cs b/src/Microsoft.AspNetCore.Blazor/Routing/NavLink.cs
index 2cfff8ccdf..bf34012707 100644
--- a/src/Microsoft.AspNetCore.Blazor/Routing/NavLink.cs
+++ b/src/Microsoft.AspNetCore.Blazor/Routing/NavLink.cs
@@ -38,11 +38,13 @@ namespace Microsoft.AspNetCore.Blazor.Routing
         /// Gets or sets the CSS class name applied to the NavLink when the 
         /// current route matches the NavLink href.
         /// </summary>
+        [Parameter]
         public string ActiveClass { get; set; }
 
         /// <summary>
         /// Gets or sets a value representing the URL matching behavior.
         /// </summary>
+        [Parameter]
         public NavLinkMatch Match { get; set; }
 
         [Inject] private IUriHelper UriHelper { get; set; }
diff --git a/src/Microsoft.AspNetCore.Blazor/Routing/Router.cs b/src/Microsoft.AspNetCore.Blazor/Routing/Router.cs
index bfbfef651c..5909ee297f 100644
--- a/src/Microsoft.AspNetCore.Blazor/Routing/Router.cs
+++ b/src/Microsoft.AspNetCore.Blazor/Routing/Router.cs
@@ -29,6 +29,7 @@ namespace Microsoft.AspNetCore.Blazor.Routing
         /// Gets or sets the assembly that should be searched, along with its referenced
         /// assemblies, for components matching the URI.
         /// </summary>
+        [Parameter]
         public Assembly AppAssembly { get; set; }
 
         private RouteTable Routes { get; set; }
diff --git a/test/Microsoft.AspNetCore.Blazor.Build.Test/BindRazorIntegrationTest.cs b/test/Microsoft.AspNetCore.Blazor.Build.Test/BindRazorIntegrationTest.cs
index deef58edeb..00f171c1f6 100644
--- a/test/Microsoft.AspNetCore.Blazor.Build.Test/BindRazorIntegrationTest.cs
+++ b/test/Microsoft.AspNetCore.Blazor.Build.Test/BindRazorIntegrationTest.cs
@@ -24,8 +24,10 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public int Value { get; set; }
 
+        [Parameter]
         public Action<int> ValueChanged { get; set; }
     }
 }"));
@@ -96,8 +98,10 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public int Value { get; set; }
 
+        [Parameter]
         public Action<int> OnChanged { get; set; }
     }
 }"));
diff --git a/test/Microsoft.AspNetCore.Blazor.Build.Test/ComponentRenderingRazorIntegrationTest.cs b/test/Microsoft.AspNetCore.Blazor.Build.Test/ComponentRenderingRazorIntegrationTest.cs
index 70435e2ff0..c67bb05357 100644
--- a/test/Microsoft.AspNetCore.Blazor.Build.Test/ComponentRenderingRazorIntegrationTest.cs
+++ b/test/Microsoft.AspNetCore.Blazor.Build.Test/ComponentRenderingRazorIntegrationTest.cs
@@ -57,10 +57,10 @@ namespace Test
 
     public class MyComponent : BlazorComponent
     {
-        public int IntProperty { get; set; }
-        public bool BoolProperty { get; set; }
-        public string StringProperty { get; set; }
-        public SomeType ObjectProperty { get; set; }
+        [Parameter] public int IntProperty { get; set; }
+        [Parameter] public bool BoolProperty { get; set; }
+        [Parameter] public string StringProperty { get; set; }
+        [Parameter] public SomeType ObjectProperty { get; set; }
     }
 }
 "));
@@ -90,6 +90,36 @@ namespace Test
                 });
         }
 
+        [Fact]
+        public void Render_ChildComponent_TriesToSetNonParamter()
+        {
+            // Arrange
+            AdditionalSyntaxTrees.Add(Parse(@"
+using Microsoft.AspNetCore.Blazor.Components;
+
+namespace Test
+{
+    public class MyComponent : BlazorComponent
+    {
+        public int IntProperty { get; set; }
+    }
+}
+"));
+
+            var component = CompileToComponent(@"
+@addTagHelper *, TestAssembly
+<MyComponent  IntProperty=""123"" />");
+
+            // Act
+            var ex = Assert.Throws<InvalidOperationException>(() => GetRenderTree(component));
+
+            // Assert
+            Assert.Equal(
+                "Object of type 'Test.MyComponent' has a property matching the name 'IntProperty', " +
+                    "but it does not have [ParameterAttribute] applied.",
+                ex.Message);
+        }
+
         [Fact]
         public void Render_ChildComponent_WithExplicitStringParameter()
         {
@@ -101,6 +131,7 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public string StringProperty { get; set; }
     }
 }
@@ -174,6 +205,7 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public Action<UIMouseEventArgs> OnClick { get; set; }
     }
 }
@@ -221,6 +253,7 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public Action<UIEventArgs> OnClick { get; set; }
     }
 }
@@ -267,6 +300,7 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public bool BoolProperty { get; set; }
     }
 }"));
@@ -296,7 +330,10 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public string MyAttr { get; set; }
+
+        [Parameter]
         public RenderFragment ChildContent { get; set; }
     }
 }
@@ -338,6 +375,7 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public RenderFragment ChildContent { get; set; }
     }
 }
diff --git a/test/Microsoft.AspNetCore.Blazor.Build.Test/DesignTimeCodeGenerationTest.cs b/test/Microsoft.AspNetCore.Blazor.Build.Test/DesignTimeCodeGenerationTest.cs
index 6d61482ed3..f5b6c31328 100644
--- a/test/Microsoft.AspNetCore.Blazor.Build.Test/DesignTimeCodeGenerationTest.cs
+++ b/test/Microsoft.AspNetCore.Blazor.Build.Test/DesignTimeCodeGenerationTest.cs
@@ -1,7 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using Microsoft.CodeAnalysis.CSharp;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Blazor.Build.Test
@@ -27,10 +26,10 @@ namespace Test
 
     public class MyComponent : BlazorComponent
     {
-        public int IntProperty { get; set; }
-        public bool BoolProperty { get; set; }
-        public string StringProperty { get; set; }
-        public SomeType ObjectProperty { get; set; }
+        [Parameter] public int IntProperty { get; set; }
+        [Parameter] public bool BoolProperty { get; set; }
+        [Parameter] public string StringProperty { get; set; }
+        [Parameter] public SomeType ObjectProperty { get; set; }
     }
 }
 "));
@@ -61,6 +60,7 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public string StringProperty { get; set; }
     }
 }
@@ -116,6 +116,7 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public Action<UIEventArgs> OnClick { get; set; }
     }
 }
@@ -152,6 +153,7 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public Action<UIEventArgs> OnClick { get; set; }
     }
 }
@@ -188,8 +190,10 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public string MyAttr { get; set; }
 
+        [Parameter]
         public RenderFragment ChildContent { get; set; }
     }
 }
@@ -382,8 +386,10 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public int Value { get; set; }
 
+        [Parameter]
         public Action<int> ValueChanged { get; set; }
     }
 }"));
@@ -446,8 +452,10 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public int Value { get; set; }
 
+        [Parameter]
         public Action<int> OnChanged { get; set; }
     }
 }"));
diff --git a/test/Microsoft.AspNetCore.Blazor.Build.Test/DirectiveRazorIntegrationTest.cs b/test/Microsoft.AspNetCore.Blazor.Build.Test/DirectiveRazorIntegrationTest.cs
index 8cc58b1b61..5b7e7a49c3 100644
--- a/test/Microsoft.AspNetCore.Blazor.Build.Test/DirectiveRazorIntegrationTest.cs
+++ b/test/Microsoft.AspNetCore.Blazor.Build.Test/DirectiveRazorIntegrationTest.cs
@@ -121,6 +121,7 @@ namespace Microsoft.AspNetCore.Blazor.Build.Test
 
         public class TestLayout : ILayoutComponent
         {
+            [Parameter]
             public RenderFragment Body { get; set; }
 
             public void Init(RenderHandle renderHandle)
diff --git a/test/Microsoft.AspNetCore.Blazor.Build.Test/RuntimeCodeGenerationTest.cs b/test/Microsoft.AspNetCore.Blazor.Build.Test/RuntimeCodeGenerationTest.cs
index 4c38e6298d..d6ddfadfce 100644
--- a/test/Microsoft.AspNetCore.Blazor.Build.Test/RuntimeCodeGenerationTest.cs
+++ b/test/Microsoft.AspNetCore.Blazor.Build.Test/RuntimeCodeGenerationTest.cs
@@ -51,10 +51,10 @@ namespace Test
 
     public class MyComponent : BlazorComponent
     {
-        public int IntProperty { get; set; }
-        public bool BoolProperty { get; set; }
-        public string StringProperty { get; set; }
-        public SomeType ObjectProperty { get; set; }
+        [Parameter] public int IntProperty { get; set; }
+        [Parameter] public bool BoolProperty { get; set; }
+        [Parameter] public string StringProperty { get; set; }
+        [Parameter] public SomeType ObjectProperty { get; set; }
     }
 }
 "));
@@ -85,6 +85,7 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public string StringProperty { get; set; }
     }
 }
@@ -141,6 +142,7 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public Action<UIEventArgs> OnClick { get; set; }
     }
 }
@@ -177,6 +179,7 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public Action<UIEventArgs> OnClick { get; set; }
     }
 }
@@ -213,8 +216,10 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public string MyAttr { get; set; }
 
+        [Parameter]
         public RenderFragment ChildContent { get; set; }
     }
 }
@@ -635,8 +640,10 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public int Value { get; set; }
 
+        [Parameter]
         public Action<int> ValueChanged { get; set; }
     }
 }"));
@@ -699,8 +706,10 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public int Value { get; set; }
 
+        [Parameter]
         public Action<int> OnChanged { get; set; }
     }
 }"));
diff --git a/test/Microsoft.AspNetCore.Blazor.Razor.Extensions.Test/BindTagHelperDescriptorProviderTest.cs b/test/Microsoft.AspNetCore.Blazor.Razor.Extensions.Test/BindTagHelperDescriptorProviderTest.cs
index a5755e1962..737f190687 100644
--- a/test/Microsoft.AspNetCore.Blazor.Razor.Extensions.Test/BindTagHelperDescriptorProviderTest.cs
+++ b/test/Microsoft.AspNetCore.Blazor.Razor.Extensions.Test/BindTagHelperDescriptorProviderTest.cs
@@ -27,8 +27,10 @@ namespace Test
 
         public void SetParameters(ParameterCollection parameters) { }
 
+        [Parameter]
         public string MyProperty { get; set; }
 
+        [Parameter]
         public Action<string> MyPropertyChanged { get; set; }
     }
 }
diff --git a/test/Microsoft.AspNetCore.Blazor.Razor.Extensions.Test/ComponentTagHelperDescriptorProviderTest.cs b/test/Microsoft.AspNetCore.Blazor.Razor.Extensions.Test/ComponentTagHelperDescriptorProviderTest.cs
index ce94193e1a..e74476b132 100644
--- a/test/Microsoft.AspNetCore.Blazor.Razor.Extensions.Test/ComponentTagHelperDescriptorProviderTest.cs
+++ b/test/Microsoft.AspNetCore.Blazor.Razor.Extensions.Test/ComponentTagHelperDescriptorProviderTest.cs
@@ -27,6 +27,7 @@ namespace Test
 
         public void SetParameters(ParameterCollection parameters) { }
 
+        [Parameter]
         public string MyProperty { get; set; }
     }
 }
@@ -136,6 +137,7 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public string MyProperty { get; set; }
     }
 }
@@ -176,6 +178,7 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public bool MyProperty { get; set; }
     }
 }
@@ -227,6 +230,7 @@ namespace Test
 
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public MyEnum MyProperty { get; set; }
     }
 }
@@ -274,6 +278,7 @@ namespace Test
 {
     public class MyComponent : BlazorComponent
     {
+        [Parameter]
         public Action<UIMouseEventArgs> OnClick { get; set; }
     }
 }
@@ -307,5 +312,61 @@ namespace Test
             Assert.False(attribute.IsStringProperty);
             Assert.True(attribute.IsDelegateProperty());
         }
+
+        [Fact] // This component has lots of properties that don't become components.
+        public void Execute_IgnoredProperties_CreatesDescriptor()
+        {
+            // Arrange
+
+            var compilation = BaseCompilation.AddSyntaxTrees(Parse(@"
+using Microsoft.AspNetCore.Blazor.Components;
+
+namespace Test
+{
+    public abstract class MyBase : BlazorComponent
+    {
+        [Parameter]
+        public string Hidden { get; set; }
+    }
+
+    public class MyComponent : MyBase
+    {
+        [Parameter]
+        public string NoPublicGetter { private get; set; }
+
+        public string NoParameterAttribute { get; set; }
+
+        // No attribute here, hides base-class property of the same name.
+        public new int Hidden { get; set; }
+
+        public string this[int i]
+        {
+            get { throw null; }
+            set { throw null; }
+        }
+    }
+}
+
+"));
+
+            Assert.Empty(compilation.GetDiagnostics());
+
+            var context = TagHelperDescriptorProviderContext.Create();
+            context.SetCompilation(compilation);
+
+            var provider = new ComponentTagHelperDescriptorProvider();
+
+            // Act
+            provider.Execute(context);
+
+            // Assert
+            var components = ExcludeBuiltInComponents(context);
+            var component = Assert.Single(components);
+
+            Assert.Equal("TestAssembly", component.AssemblyName);
+            Assert.Equal("Test.MyComponent", component.Name);
+
+            Assert.Empty(component.BoundAttributes);
+        }
     }
 }
diff --git a/test/Microsoft.AspNetCore.Blazor.Test/LayoutTest.cs b/test/Microsoft.AspNetCore.Blazor.Test/LayoutTest.cs
index 3a16601478..c303fbbee3 100644
--- a/test/Microsoft.AspNetCore.Blazor.Test/LayoutTest.cs
+++ b/test/Microsoft.AspNetCore.Blazor.Test/LayoutTest.cs
@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using Microsoft.AspNetCore.Blazor.Components;
 using Microsoft.AspNetCore.Blazor.Layouts;
 using Microsoft.AspNetCore.Blazor.RenderTree;
 using Microsoft.AspNetCore.Blazor.Test.Helpers;
@@ -219,6 +220,7 @@ namespace Microsoft.AspNetCore.Blazor.Test
 
         private class RootLayout : AutoRenderComponent, ILayoutComponent
         {
+            [Parameter]
             public RenderFragment Body { get; set; }
 
             protected override void BuildRenderTree(RenderTreeBuilder builder)
@@ -232,6 +234,7 @@ namespace Microsoft.AspNetCore.Blazor.Test
         [Layout(typeof(RootLayout))]
         private class NestedLayout : AutoRenderComponent, ILayoutComponent
         {
+            [Parameter]
             public RenderFragment Body { get; set; }
 
             protected override void BuildRenderTree(RenderTreeBuilder builder)
diff --git a/test/Microsoft.AspNetCore.Blazor.Test/RenderTreeDiffBuilderTest.cs b/test/Microsoft.AspNetCore.Blazor.Test/RenderTreeDiffBuilderTest.cs
index 00598122dd..a53c433ae6 100644
--- a/test/Microsoft.AspNetCore.Blazor.Test/RenderTreeDiffBuilderTest.cs
+++ b/test/Microsoft.AspNetCore.Blazor.Test/RenderTreeDiffBuilderTest.cs
@@ -1503,12 +1503,23 @@ namespace Microsoft.AspNetCore.Blazor.Test
 
         private class FakeComponent : IComponent
         {
+            [Parameter]
             public int IntProperty { get; set; }
+
+            [Parameter]
             public string StringProperty { get; set; }
+
+            [Parameter]
             public object ObjectProperty { get; set; }
+
+            [Parameter]
             public string ReadonlyProperty { get; private set; }
+
+            [Parameter]
             private string PrivateProperty { get; set; }
 
+            public string NonParameterProperty { get; set; }
+
             public void Init(RenderHandle renderHandle) { }
             public void SetParameters(ParameterCollection parameters)
             {
diff --git a/test/Microsoft.AspNetCore.Blazor.Test/RendererTest.cs b/test/Microsoft.AspNetCore.Blazor.Test/RendererTest.cs
index 87ba995fe7..af7215c3a4 100644
--- a/test/Microsoft.AspNetCore.Blazor.Test/RendererTest.cs
+++ b/test/Microsoft.AspNetCore.Blazor.Test/RendererTest.cs
@@ -1109,6 +1109,7 @@ namespace Microsoft.AspNetCore.Blazor.Test
 
         private class MessageComponent : AutoRenderComponent
         {
+            [Parameter]
             public string Message { get; set; }
 
             protected override void BuildRenderTree(RenderTreeBuilder builder)
@@ -1119,9 +1120,15 @@ namespace Microsoft.AspNetCore.Blazor.Test
 
         private class FakeComponent : IComponent
         {
+            [Parameter]
             public int IntProperty { get; set; }
+
+            [Parameter]
             public string StringProperty { get; set; }
+
+            [Parameter]
             public object ObjectProperty { get; set; }
+
             public RenderHandle RenderHandle { get; private set; }
 
             public void Init(RenderHandle renderHandle)
@@ -1133,8 +1140,13 @@ namespace Microsoft.AspNetCore.Blazor.Test
 
         private class EventComponent : AutoRenderComponent, IComponent, IHandleEvent
         {
+            [Parameter]
             public Action<UIEventArgs> OnTest { get; set; }
+
+            [Parameter]
             public Action<UIMouseEventArgs> OnClick { get; set; }
+
+            [Parameter]
             public Action OnClickAction { get; set; }
 
             public bool SkipElement { get; set; }
@@ -1174,7 +1186,10 @@ namespace Microsoft.AspNetCore.Blazor.Test
 
         private class ConditionalParentComponent<T> : AutoRenderComponent where T : IComponent
         {
+            [Parameter]
             public bool IncludeChild { get; set; }
+
+            [Parameter]
             public IDictionary<string, object> ChildParameters { get; set; }
 
             protected override void BuildRenderTree(RenderTreeBuilder builder)
@@ -1199,6 +1214,7 @@ namespace Microsoft.AspNetCore.Blazor.Test
         
         private class ReRendersParentComponent : AutoRenderComponent
         {
+            [Parameter]
             public TestComponent Parent { get; set; }
             private bool _isFirstTime = true;
 
@@ -1216,6 +1232,7 @@ namespace Microsoft.AspNetCore.Blazor.Test
 
         private class RendersSelfAfterEventComponent : IComponent, IHandleEvent
         {
+            [Parameter]
             public Action<object> OnClick { get; set; }
 
             private RenderHandle _renderHandle;
diff --git a/test/testapps/BasicTestApp/MessageComponent.cshtml b/test/testapps/BasicTestApp/MessageComponent.cshtml
index 51ce2cc47d..24845cacc1 100644
--- a/test/testapps/BasicTestApp/MessageComponent.cshtml
+++ b/test/testapps/BasicTestApp/MessageComponent.cshtml
@@ -1,4 +1,5 @@
-<span style="color: red" class="message">@Message</span>
+@using Microsoft.AspNetCore.Blazor.Components
+<span style="color: red" class="message">@Message</span>
 @functions {
-    public string Message { get; set; }
+    [Parameter] public string Message { get; set; }
 }
diff --git a/test/testapps/BasicTestApp/PassThroughContentComponent.cshtml b/test/testapps/BasicTestApp/PassThroughContentComponent.cshtml
index 796347b04f..b9f2d947da 100644
--- a/test/testapps/BasicTestApp/PassThroughContentComponent.cshtml
+++ b/test/testapps/BasicTestApp/PassThroughContentComponent.cshtml
@@ -1,8 +1,9 @@
 @using Microsoft.AspNetCore.Blazor
+@using Microsoft.AspNetCore.Blazor.Components
 @ChildContent
 @functions {
     // Note: The lack of any whitespace or other output besides @ChildContent is important for
     // what scenarios this component is used for in E2E tests.
 
-    public RenderFragment ChildContent { get; set; }
+    [Parameter] public RenderFragment ChildContent { get; set; }
 }
diff --git a/test/testapps/BasicTestApp/PropertiesChangedHandlerChild.cshtml b/test/testapps/BasicTestApp/PropertiesChangedHandlerChild.cshtml
index caa5c46849..01982d241d 100644
--- a/test/testapps/BasicTestApp/PropertiesChangedHandlerChild.cshtml
+++ b/test/testapps/BasicTestApp/PropertiesChangedHandlerChild.cshtml
@@ -1,7 +1,9 @@
-<div class="supplied">You supplied: @SuppliedValue</div>
+@using Microsoft.AspNetCore.Blazor.Components
+<div class="supplied">You supplied: @SuppliedValue</div>
 <div class="computed">I computed: @computedValue</div>
 
 @functions {
+    [Parameter]
     public int SuppliedValue { get; set; }
 
     private int computedValue;
diff --git a/test/testapps/BasicTestApp/RouterTest/WithParameters.cshtml b/test/testapps/BasicTestApp/RouterTest/WithParameters.cshtml
index b213ef4845..1b54e1348f 100644
--- a/test/testapps/BasicTestApp/RouterTest/WithParameters.cshtml
+++ b/test/testapps/BasicTestApp/RouterTest/WithParameters.cshtml
@@ -1,11 +1,14 @@
 @page "/RouterTest/WithParameters/Name/{firstName}/LastName/{lastName}"
 @using BasicTestApp.RouterTest
+@using Microsoft.AspNetCore.Blazor.Components
 <div id="test-info">Your full name is @FirstName @LastName.</div>
 <Links />
 
 @functions
 {
+    [Parameter]
     public string FirstName { get; set; }
 
+    [Parameter]
     public string LastName { get ; set; }
 }