diff --git a/build/dependencies.props b/build/dependencies.props
index 8fed603b93..22824154bd 100644
--- a/build/dependencies.props
+++ b/build/dependencies.props
@@ -48,8 +48,8 @@
     <MicrosoftAspNetCoreRazorTagHelpersTestingSourcesPackageVersion>2.2.0-preview3-35252</MicrosoftAspNetCoreRazorTagHelpersTestingSourcesPackageVersion>
     <MicrosoftAspNetCoreResponseCachingAbstractionsPackageVersion>2.2.0-preview3-35252</MicrosoftAspNetCoreResponseCachingAbstractionsPackageVersion>
     <MicrosoftAspNetCoreResponseCachingPackageVersion>2.2.0-preview3-35252</MicrosoftAspNetCoreResponseCachingPackageVersion>
-    <MicrosoftAspNetCoreRoutingAbstractionsPackageVersion>2.2.0-preview3-35252</MicrosoftAspNetCoreRoutingAbstractionsPackageVersion>
-    <MicrosoftAspNetCoreRoutingPackageVersion>2.2.0-preview3-35252</MicrosoftAspNetCoreRoutingPackageVersion>
+    <MicrosoftAspNetCoreRoutingAbstractionsPackageVersion>2.2.0-a-preview3-outbound-parameter-tranformer-16996</MicrosoftAspNetCoreRoutingAbstractionsPackageVersion>
+    <MicrosoftAspNetCoreRoutingPackageVersion>2.2.0-a-preview3-outbound-parameter-tranformer-16996</MicrosoftAspNetCoreRoutingPackageVersion>
     <MicrosoftAspNetCoreServerIISIntegrationPackageVersion>2.2.0-preview3-35252</MicrosoftAspNetCoreServerIISIntegrationPackageVersion>
     <MicrosoftAspNetCoreServerKestrelPackageVersion>2.2.0-preview3-35252</MicrosoftAspNetCoreServerKestrelPackageVersion>
     <MicrosoftAspNetCoreSessionPackageVersion>2.2.0-preview3-35252</MicrosoftAspNetCoreSessionPackageVersion>
diff --git a/src/Microsoft.AspNetCore.Mvc.Core/ApplicationModels/AttributeRouteModel.cs b/src/Microsoft.AspNetCore.Mvc.Core/ApplicationModels/AttributeRouteModel.cs
index 3283a630a0..4623d67090 100644
--- a/src/Microsoft.AspNetCore.Mvc.Core/ApplicationModels/AttributeRouteModel.cs
+++ b/src/Microsoft.AspNetCore.Mvc.Core/ApplicationModels/AttributeRouteModel.cs
@@ -225,7 +225,7 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
             return ReplaceTokens(template, values, routeTokenTransformer: null);
         }
 
-        public static string ReplaceTokens(string template, IDictionary<string, string> values, IParameterTransformer routeTokenTransformer)
+        public static string ReplaceTokens(string template, IDictionary<string, string> values, IOutboundParameterTransformer routeTokenTransformer)
         {
             var builder = new StringBuilder();
             var state = TemplateParserState.Plaintext;
@@ -379,7 +379,7 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
 
                             if (routeTokenTransformer != null)
                             {
-                                value = routeTokenTransformer.Transform(value);
+                                value = routeTokenTransformer.TransformOutbound(value);
                             }
 
                             builder.Append(value);
diff --git a/src/Microsoft.AspNetCore.Mvc.Core/ApplicationModels/RouteTokenTransformerConvention.cs b/src/Microsoft.AspNetCore.Mvc.Core/ApplicationModels/RouteTokenTransformerConvention.cs
index d7645077af..c83ba6cc47 100644
--- a/src/Microsoft.AspNetCore.Mvc.Core/ApplicationModels/RouteTokenTransformerConvention.cs
+++ b/src/Microsoft.AspNetCore.Mvc.Core/ApplicationModels/RouteTokenTransformerConvention.cs
@@ -8,17 +8,17 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
 {
     /// <summary>
     /// An <see cref="IActionModelConvention"/> that sets attribute routing token replacement
-    /// to use the specified <see cref="IParameterTransformer"/> on <see cref="ActionModel"/> selectors.
+    /// to use the specified <see cref="IOutboundParameterTransformer"/> on <see cref="ActionModel"/> selectors.
     /// </summary>
     public class RouteTokenTransformerConvention : IActionModelConvention
     {
-        private readonly IParameterTransformer _parameterTransformer;
+        private readonly IOutboundParameterTransformer _parameterTransformer;
 
         /// <summary>
-        /// Creates a new instance of <see cref="RouteTokenTransformerConvention"/> with the specified <see cref="IParameterTransformer"/>.
+        /// Creates a new instance of <see cref="RouteTokenTransformerConvention"/> with the specified <see cref="IOutboundParameterTransformer"/>.
         /// </summary>
-        /// <param name="parameterTransformer">The <see cref="IParameterTransformer"/> to use with attribute routing token replacement.</param>
-        public RouteTokenTransformerConvention(IParameterTransformer parameterTransformer)
+        /// <param name="parameterTransformer">The <see cref="IOutboundParameterTransformer"/> to use with attribute routing token replacement.</param>
+        public RouteTokenTransformerConvention(IOutboundParameterTransformer parameterTransformer)
         {
             if (parameterTransformer == null)
             {
@@ -32,7 +32,7 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
         {
             if (ShouldApply(action))
             {
-                action.Properties[typeof(IParameterTransformer)] = _parameterTransformer;
+                action.Properties[typeof(IOutboundParameterTransformer)] = _parameterTransformer;
             }
         }
 
diff --git a/src/Microsoft.AspNetCore.Mvc.Core/Internal/ControllerActionDescriptorBuilder.cs b/src/Microsoft.AspNetCore.Mvc.Core/Internal/ControllerActionDescriptorBuilder.cs
index 174457bbcc..21ec3aee6b 100644
--- a/src/Microsoft.AspNetCore.Mvc.Core/Internal/ControllerActionDescriptorBuilder.cs
+++ b/src/Microsoft.AspNetCore.Mvc.Core/Internal/ControllerActionDescriptorBuilder.cs
@@ -390,8 +390,8 @@ namespace Microsoft.AspNetCore.Mvc.Internal
         {
             try
             {
-                actionDescriptor.Properties.TryGetValue(typeof(IParameterTransformer), out var transformer);
-                var routeTokenTransformer = transformer as IParameterTransformer;
+                actionDescriptor.Properties.TryGetValue(typeof(IOutboundParameterTransformer), out var transformer);
+                var routeTokenTransformer = transformer as IOutboundParameterTransformer;
 
                 actionDescriptor.AttributeRouteInfo.Template = AttributeRouteModel.ReplaceTokens(
                     actionDescriptor.AttributeRouteInfo.Template,
diff --git a/src/Microsoft.AspNetCore.Mvc.Core/Internal/MvcEndpointDataSource.cs b/src/Microsoft.AspNetCore.Mvc.Core/Internal/MvcEndpointDataSource.cs
index 0c7a0f74f0..0a1aa08e24 100644
--- a/src/Microsoft.AspNetCore.Mvc.Core/Internal/MvcEndpointDataSource.cs
+++ b/src/Microsoft.AspNetCore.Mvc.Core/Internal/MvcEndpointDataSource.cs
@@ -277,9 +277,9 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                             // Use the first transformer policy
                             for (var k = 0; k < parameterPolicies.Count; k++)
                             {
-                                if (parameterPolicies[k] is IParameterTransformer parameterTransformer)
+                                if (parameterPolicies[k] is IOutboundParameterTransformer parameterTransformer)
                                 {
-                                    parameterRouteValue = parameterTransformer.Transform(parameterRouteValue);
+                                    parameterRouteValue = parameterTransformer.TransformOutbound(parameterRouteValue);
                                     break;
                                 }
                             }
diff --git a/test/Microsoft.AspNetCore.Mvc.Core.Test/ApplicationModels/RouteTokenTransformerConventionTest.cs b/test/Microsoft.AspNetCore.Mvc.Core.Test/ApplicationModels/RouteTokenTransformerConventionTest.cs
index aabefa456e..807bb4d41a 100644
--- a/test/Microsoft.AspNetCore.Mvc.Core.Test/ApplicationModels/RouteTokenTransformerConventionTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Core.Test/ApplicationModels/RouteTokenTransformerConventionTest.cs
@@ -47,7 +47,7 @@ namespace Microsoft.AspNetCore.Mvc.Test.ApplicationModels
             convention.Apply(model);
 
             // Assert
-            Assert.True(model.Properties.TryGetValue(typeof(IParameterTransformer), out var routeTokenTransformer));
+            Assert.True(model.Properties.TryGetValue(typeof(IOutboundParameterTransformer), out var routeTokenTransformer));
             Assert.Equal(transformer, routeTokenTransformer);
         }
 
@@ -68,7 +68,7 @@ namespace Microsoft.AspNetCore.Mvc.Test.ApplicationModels
             convention.Apply(model);
 
             // Assert
-            Assert.False(model.Properties.TryGetValue(typeof(IParameterTransformer), out _));
+            Assert.False(model.Properties.TryGetValue(typeof(IOutboundParameterTransformer), out _));
         }
 
         private MethodInfo GetMethodInfo()
@@ -76,17 +76,17 @@ namespace Microsoft.AspNetCore.Mvc.Test.ApplicationModels
             return typeof(RouteTokenTransformerConventionTest).GetMethod(nameof(GetMethodInfo), BindingFlags.NonPublic | BindingFlags.Instance);
         }
 
-        private class TestParameterTransformer : IParameterTransformer
+        private class TestParameterTransformer : IOutboundParameterTransformer
         {
-            public string Transform(string value)
+            public string TransformOutbound(object value)
             {
-                return value;
+                return value?.ToString();
             }
         }
 
         private class CustomRouteTokenTransformerConvention : RouteTokenTransformerConvention
         {
-            public CustomRouteTokenTransformerConvention(IParameterTransformer parameterTransformer) : base(parameterTransformer)
+            public CustomRouteTokenTransformerConvention(IOutboundParameterTransformer parameterTransformer) : base(parameterTransformer)
             {
             }
 
diff --git a/test/Microsoft.AspNetCore.Mvc.Core.Test/Internal/MvcEndpointDataSourceTests.cs b/test/Microsoft.AspNetCore.Mvc.Core.Test/Internal/MvcEndpointDataSourceTests.cs
index 21fd57a11b..168ae2950f 100644
--- a/test/Microsoft.AspNetCore.Mvc.Core.Test/Internal/MvcEndpointDataSourceTests.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Core.Test/Internal/MvcEndpointDataSourceTests.cs
@@ -771,11 +771,11 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             return dataSource;
         }
 
-        private class UpperCaseParameterTransform : IParameterTransformer
+        private class UpperCaseParameterTransform : IOutboundParameterTransformer
         {
-            public string Transform(string value)
+            public string TransformOutbound(object value)
             {
-                return value?.ToUpperInvariant();
+                return value?.ToString().ToUpperInvariant();
             }
         }
 
diff --git a/test/WebSites/RoutingWebSite/ControllerRouteTokenTransformerConvention.cs b/test/WebSites/RoutingWebSite/ControllerRouteTokenTransformerConvention.cs
index 37dca3f259..d2b179a25b 100644
--- a/test/WebSites/RoutingWebSite/ControllerRouteTokenTransformerConvention.cs
+++ b/test/WebSites/RoutingWebSite/ControllerRouteTokenTransformerConvention.cs
@@ -11,9 +11,9 @@ namespace RoutingWebSite
     public class ControllerRouteTokenTransformerConvention : IApplicationModelConvention
     {
         private readonly Type _controllerType;
-        private readonly IParameterTransformer _parameterTransformer;
+        private readonly IOutboundParameterTransformer _parameterTransformer;
 
-        public ControllerRouteTokenTransformerConvention(Type controllerType, IParameterTransformer parameterTransformer)
+        public ControllerRouteTokenTransformerConvention(Type controllerType, IOutboundParameterTransformer parameterTransformer)
         {
             if (parameterTransformer == null)
             {
@@ -30,7 +30,7 @@ namespace RoutingWebSite
             {
                 foreach (var action in controller.Actions)
                 {
-                    action.Properties[typeof(IParameterTransformer)] = _parameterTransformer;
+                    action.Properties[typeof(IOutboundParameterTransformer)] = _parameterTransformer;
                 }
             }
         }
diff --git a/test/WebSites/RoutingWebSite/TestParameterTransformer.cs b/test/WebSites/RoutingWebSite/TestParameterTransformer.cs
index 779d483ca6..a1aa4088f6 100644
--- a/test/WebSites/RoutingWebSite/TestParameterTransformer.cs
+++ b/test/WebSites/RoutingWebSite/TestParameterTransformer.cs
@@ -7,12 +7,12 @@ using Microsoft.AspNetCore.Routing;
 
 namespace RoutingWebSite
 {
-    public class SlugifyParameterTransformer : IParameterTransformer
+    public class SlugifyParameterTransformer : IOutboundParameterTransformer
     {
-        public string Transform(string value)
+        public string TransformOutbound(object value)
         {
             // Slugify value
-            return Regex.Replace(value, "([a-z])([A-Z])", "$1-$2", RegexOptions.None, TimeSpan.FromMilliseconds(100)).ToLower();
+            return value == null ? null : Regex.Replace(value.ToString(), "([a-z])([A-Z])", "$1-$2", RegexOptions.None, TimeSpan.FromMilliseconds(100)).ToLower();
         }
     }
 }
\ No newline at end of file