diff --git a/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/ActionModel.cs b/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/ActionModel.cs
index c1ea508f90..0829b27abc 100644
--- a/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/ActionModel.cs
+++ b/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/ActionModel.cs
@@ -48,7 +48,7 @@ namespace Microsoft.AspNet.Mvc.ApplicationModels
             }
         }
 
-        public List<IActionConstraintMetadata> ActionConstraints { get; private set; }
+        public IList<IActionConstraintMetadata> ActionConstraints { get; private set; }
 
         public MethodInfo ActionMethod { get; }
 
@@ -69,12 +69,12 @@ namespace Microsoft.AspNet.Mvc.ApplicationModels
 
         public ControllerModel Controller { get; set; }
 
-        public List<IFilter> Filters { get; private set; }
+        public IList<IFilter> Filters { get; private set; }
 
-        public List<string> HttpMethods { get; private set; }
+        public IList<string> HttpMethods { get; private set; }
 
-        public List<ParameterModel> Parameters { get; private set; }
+        public IList<ParameterModel> Parameters { get; private set; }
 
-        public List<IRouteConstraintProvider> RouteConstraints { get; private set; }
+        public IList<IRouteConstraintProvider> RouteConstraints { get; private set; }
     }
 }
diff --git a/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/ApplicationModel.cs b/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/ApplicationModel.cs
index e102fbefca..cbb87b98d8 100644
--- a/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/ApplicationModel.cs
+++ b/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/ApplicationModel.cs
@@ -13,8 +13,8 @@ namespace Microsoft.AspNet.Mvc.ApplicationModels
             Filters = new List<IFilter>();
         }
 
-        public List<ControllerModel> Controllers { get; private set; }
+        public IList<ControllerModel> Controllers { get; private set; }
 
-        public List<IFilter> Filters { get; private set; }
+        public IList<IFilter> Filters { get; private set; }
     }
 }
\ No newline at end of file
diff --git a/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/ControllerModel.cs b/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/ControllerModel.cs
index 9b5ee6c2dd..ef22386b47 100644
--- a/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/ControllerModel.cs
+++ b/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/ControllerModel.cs
@@ -44,9 +44,9 @@ namespace Microsoft.AspNet.Mvc.ApplicationModels
                 other.AttributeRoutes.Select(a => new AttributeRouteModel(a)));
         }
 
-        public List<IActionConstraintMetadata> ActionConstraints { get; private set; }
+        public IList<IActionConstraintMetadata> ActionConstraints { get; private set; }
 
-        public List<ActionModel> Actions { get; private set; }
+        public IList<ActionModel> Actions { get; private set; }
 
         /// <summary>
         /// Gets or sets the <see cref="ApiExplorerModel"/> for this controller.
@@ -55,7 +55,7 @@ namespace Microsoft.AspNet.Mvc.ApplicationModels
 
         public ApplicationModel Application { get; set; }
 
-        public List<AttributeRouteModel> AttributeRoutes { get; private set; }
+        public IList<AttributeRouteModel> AttributeRoutes { get; private set; }
 
         public IReadOnlyList<object> Attributes { get; }
 
@@ -63,8 +63,8 @@ namespace Microsoft.AspNet.Mvc.ApplicationModels
 
         public TypeInfo ControllerType { get; private set; }
 
-        public List<IFilter> Filters { get; private set; }
+        public IList<IFilter> Filters { get; private set; }
 
-        public List<IRouteConstraintProvider> RouteConstraints { get; private set; }
+        public IList<IRouteConstraintProvider> RouteConstraints { get; private set; }
     }
 }
diff --git a/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/DefaultActionModelBuilder.cs b/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/DefaultActionModelBuilder.cs
index 4bc8b26271..d9afde3509 100644
--- a/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/DefaultActionModelBuilder.cs
+++ b/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/DefaultActionModelBuilder.cs
@@ -254,8 +254,8 @@ namespace Microsoft.AspNet.Mvc.ApplicationModels
         {
             var actionModel = new ActionModel(methodInfo, attributes);
 
-            actionModel.ActionConstraints.AddRange(attributes.OfType<IActionConstraintMetadata>());
-            actionModel.Filters.AddRange(attributes.OfType<IFilter>());
+            AddRange(actionModel.ActionConstraints, attributes.OfType<IActionConstraintMetadata>());
+            AddRange(actionModel.Filters, attributes.OfType<IFilter>());
 
             var actionName = attributes.OfType<ActionNameAttribute>().FirstOrDefault();
             if (actionName?.Name != null)
@@ -280,13 +280,13 @@ namespace Microsoft.AspNet.Mvc.ApplicationModels
             }
 
             var httpMethods = attributes.OfType<IActionHttpMethodProvider>();
-            actionModel.HttpMethods.AddRange(
+            AddRange(actionModel.HttpMethods,
                 httpMethods
                     .Where(a => a.HttpMethods != null)
                     .SelectMany(a => a.HttpMethods)
                     .Distinct());
 
-            actionModel.RouteConstraints.AddRange(attributes.OfType<IRouteConstraintProvider>());
+            AddRange(actionModel.RouteConstraints, attributes.OfType<IRouteConstraintProvider>());
 
             var routeTemplateProvider =
                 attributes
@@ -329,5 +329,13 @@ namespace Microsoft.AspNet.Mvc.ApplicationModels
                 routeTemplateProvider.Order == null &&
                 routeTemplateProvider.Name == null;
         }
+
+        private static void AddRange<T>(IList<T> list, IEnumerable<T> items)
+        {
+            foreach (var item in items)
+            {
+                list.Add(item);
+            }
+        }
     }
 }
\ No newline at end of file
diff --git a/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/DefaultControllerModelBuilder.cs b/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/DefaultControllerModelBuilder.cs
index b8fa51f4d5..d4cb7cfed2 100644
--- a/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/DefaultControllerModelBuilder.cs
+++ b/src/Microsoft.AspNet.Mvc.Core/ApplicationModels/DefaultControllerModelBuilder.cs
@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
 using Microsoft.AspNet.Mvc.Description;
@@ -120,11 +121,12 @@ namespace Microsoft.AspNet.Mvc.ApplicationModels
                     typeInfo.Name.Substring(0, typeInfo.Name.Length - "Controller".Length) :
                     typeInfo.Name;
 
-            controllerModel.ActionConstraints.AddRange(attributes.OfType<IActionConstraintMetadata>());
-            controllerModel.Filters.AddRange(attributes.OfType<IFilter>());
-            controllerModel.RouteConstraints.AddRange(attributes.OfType<IRouteConstraintProvider>());
+            AddRange(controllerModel.ActionConstraints, attributes.OfType<IActionConstraintMetadata>());
+            AddRange(controllerModel.Filters, attributes.OfType<IFilter>());
+            AddRange(controllerModel.RouteConstraints, attributes.OfType<IRouteConstraintProvider>());
 
-            controllerModel.AttributeRoutes.AddRange(
+            AddRange(
+                controllerModel.AttributeRoutes,
                 attributes.OfType<IRouteTemplateProvider>().Select(rtp => new AttributeRouteModel(rtp)));
 
             var apiVisibility = attributes.OfType<IApiDescriptionVisibilityProvider>().FirstOrDefault();
@@ -141,5 +143,13 @@ namespace Microsoft.AspNet.Mvc.ApplicationModels
 
             return controllerModel;
         }
+
+        private static void AddRange<T>(IList<T> list, IEnumerable<T> items)
+        {
+            foreach (var item in items)
+            {
+                list.Add(item);
+            }
+        }
     }
 }
diff --git a/src/Microsoft.AspNet.Mvc.Core/ControllerActionDescriptorProvider.cs b/src/Microsoft.AspNet.Mvc.Core/ControllerActionDescriptorProvider.cs
index c727fea474..347591e91b 100644
--- a/src/Microsoft.AspNet.Mvc.Core/ControllerActionDescriptorProvider.cs
+++ b/src/Microsoft.AspNet.Mvc.Core/ControllerActionDescriptorProvider.cs
@@ -61,7 +61,10 @@ namespace Microsoft.AspNet.Mvc
         public ApplicationModel BuildModel()
         {
             var applicationModel = new ApplicationModel();
-            applicationModel.Filters.AddRange(_globalFilters);
+            foreach (var filter in _globalFilters)
+            {
+                applicationModel.Filters.Add(filter);
+            }
 
             var assemblies = _assemblyProvider.CandidateAssemblies;
             var types = assemblies.SelectMany(a => a.DefinedTypes);
diff --git a/src/Microsoft.AspNet.Mvc.Core/Logging/ActionModelValues.cs b/src/Microsoft.AspNet.Mvc.Core/Logging/ActionModelValues.cs
index 661a2cab65..f5f8d599aa 100644
--- a/src/Microsoft.AspNet.Mvc.Core/Logging/ActionModelValues.cs
+++ b/src/Microsoft.AspNet.Mvc.Core/Logging/ActionModelValues.cs
@@ -55,19 +55,19 @@ namespace Microsoft.AspNet.Mvc.Logging
         /// The parameters of the action as <see cref="ParameterModelValues"/>. 
         /// See <see cref="ActionModel.Parameters"/>.
         /// </summary>
-        public List<ParameterModelValues> Parameters { get; }
+        public IList<ParameterModelValues> Parameters { get; }
 
         /// <summary>
         /// The filters of the action as <see cref="FilterValues"/>. 
         /// See <see cref="ActionModel.Filters"/>.
         /// </summary>
-        public List<FilterValues> Filters { get; }
+        public IList<FilterValues> Filters { get; }
         
         /// <summary>
         /// The route constraints on the controller as <see cref="RouteConstraintProviderValues"/>.
         /// See <see cref="ControllerModel.RouteConstraints"/>.
         /// </summary>
-        public List<RouteConstraintProviderValues> RouteConstraints { get; set; }
+        public IList<RouteConstraintProviderValues> RouteConstraints { get; set; }
 
         /// <summary>
         /// The attribute route model of the action as <see cref="AttributeRouteModelValues"/>.
@@ -78,13 +78,13 @@ namespace Microsoft.AspNet.Mvc.Logging
         /// <summary>
         /// The http methods this action supports. See <see cref="ActionModel.HttpMethods"/>.
         /// </summary>
-        public List<string> HttpMethods { get; }
+        public IList<string> HttpMethods { get; }
 
         /// <summary>
         /// The action constraints of the action as <see cref="ActionConstraintValues"/>.
         /// See <see cref="ActionModel.ActionConstraints"/>.
         /// </summary>
-        public List<ActionConstraintValues> ActionConstraints { get; }
+        public IList<ActionConstraintValues> ActionConstraints { get; }
 
         public override string Format()
         {
diff --git a/src/Microsoft.AspNet.Mvc.WebApiCompatShim/Conventions/WebApiActionConventionsApplicationModelConvention.cs b/src/Microsoft.AspNet.Mvc.WebApiCompatShim/Conventions/WebApiActionConventionsApplicationModelConvention.cs
index bbf47089eb..0f7b36016a 100644
--- a/src/Microsoft.AspNet.Mvc.WebApiCompatShim/Conventions/WebApiActionConventionsApplicationModelConvention.cs
+++ b/src/Microsoft.AspNet.Mvc.WebApiCompatShim/Conventions/WebApiActionConventionsApplicationModelConvention.cs
@@ -57,7 +57,10 @@ namespace Microsoft.AspNet.Mvc.WebApiCompatShim
                 }
             }
 
-            controller.Actions.AddRange(newActions);
+            foreach (var action in newActions)
+            {
+                controller.Actions.Add(action);
+            }
         }
 
         private bool IsActionAttributeRouted(ActionModel action)
diff --git a/test/Microsoft.AspNet.Mvc.Core.Test/ApplicationModel/DefaultActionModelBuilderTest.cs b/test/Microsoft.AspNet.Mvc.Core.Test/ApplicationModel/DefaultActionModelBuilderTest.cs
index ee81a9b625..0223c7098b 100644
--- a/test/Microsoft.AspNet.Mvc.Core.Test/ApplicationModel/DefaultActionModelBuilderTest.cs
+++ b/test/Microsoft.AspNet.Mvc.Core.Test/ApplicationModel/DefaultActionModelBuilderTest.cs
@@ -576,7 +576,7 @@ namespace Microsoft.AspNet.Mvc.ApplicationModels
 
             // Assert
             var action = Assert.Single(actions);
-            Assert.Equal(new string[] { "GET" }, action.HttpMethods);
+            Assert.Equal<string>(new string[] { "GET" }, action.HttpMethods);
             Assert.Equal("Products", action.AttributeRouteModel.Template);
         }
 
@@ -595,10 +595,10 @@ namespace Microsoft.AspNet.Mvc.ApplicationModels
             Assert.Equal(2, actions.Count());
 
             var action = Assert.Single(actions, a => a.AttributeRouteModel.Template == "Products");
-            Assert.Equal(new string[] { "GET", "POST" }, action.HttpMethods);
+            Assert.Equal<string>(new string[] { "GET", "POST" }, action.HttpMethods);
 
             action = Assert.Single(actions, a => a.AttributeRouteModel.Template == "v2/Products");
-            Assert.Equal(new string[] { "GET", "POST" }, action.HttpMethods);
+            Assert.Equal<string>(new string[] { "GET", "POST" }, action.HttpMethods);
         }
 
         [Fact]
@@ -616,13 +616,13 @@ namespace Microsoft.AspNet.Mvc.ApplicationModels
             Assert.Equal(3, actions.Count());
 
             var action = Assert.Single(actions, a => a.AttributeRouteModel.Template == "Products");
-            Assert.Equal(new string[] { "GET" }, action.HttpMethods);
+            Assert.Equal<string>(new string[] { "GET" }, action.HttpMethods);
 
             action = Assert.Single(actions, a => a.AttributeRouteModel.Template == "v2/Products");
-            Assert.Equal(new string[] { "GET" }, action.HttpMethods);
+            Assert.Equal<string>(new string[] { "GET" }, action.HttpMethods);
 
             action = Assert.Single(actions, a => a.AttributeRouteModel.Template == "Products/Buy");
-            Assert.Equal(new string[] { "POST" }, action.HttpMethods);
+            Assert.Equal<string>(new string[] { "POST" }, action.HttpMethods);
         }
 
         [Fact]
@@ -640,10 +640,10 @@ namespace Microsoft.AspNet.Mvc.ApplicationModels
             Assert.Equal(2, actions.Count());
 
             var action = Assert.Single(actions, a => a.AttributeRouteModel?.Template == "Products");
-            Assert.Equal(new string[] { "POST" }, action.HttpMethods);
+            Assert.Equal<string>(new string[] { "POST" }, action.HttpMethods);
 
             action = Assert.Single(actions, a => a.AttributeRouteModel?.Template == null);
-            Assert.Equal(new string[] { "GET" }, action.HttpMethods);
+            Assert.Equal<string>(new string[] { "GET" }, action.HttpMethods);
         }
 
         private class AccessibleActionModelBuilder : DefaultActionModelBuilder