diff --git a/src/Microsoft.AspNetCore.Mvc.Razor/RazorPage.cs b/src/Microsoft.AspNetCore.Mvc.Razor/RazorPage.cs
index bab23fd534..6196e64b51 100644
--- a/src/Microsoft.AspNetCore.Mvc.Razor/RazorPage.cs
+++ b/src/Microsoft.AspNetCore.Mvc.Razor/RazorPage.cs
@@ -18,13 +18,21 @@ namespace Microsoft.AspNetCore.Mvc.Razor
     /// <summary>
     /// Represents properties and methods that are needed in order to render a view that uses Razor syntax.
     /// </summary>
-    public abstract class RazorPage : RazorPageBase, IRazorPage
+    public abstract class RazorPage : RazorPageBase
     {
         private readonly HashSet<string> _renderedSections = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
         private bool _renderedBody;
         private bool _ignoreBody;
         private HashSet<string> _ignoredSections;
 
+        /// <summary>
+        /// Initializes a new instance of <see cref="RazorPage"/>.
+        /// </summary>
+        public RazorPage()
+        {
+
+        }
+
         /// <summary>
         /// Gets the <see cref="System.Text.Encodings.Web.HtmlEncoder"/> to use when this <see cref="RazorPage"/>
         /// handles non-<see cref="IHtmlContent"/> C# expressions.
@@ -49,12 +57,6 @@ namespace Microsoft.AspNetCore.Mvc.Razor
         /// <remarks>Returns null if <see cref="ViewContext"/> is null.</remarks>
         public ITempDataDictionary TempData => ViewContext?.TempData;
 
-        /// <inheritdoc />
-        public IHtmlContent BodyContent { get; set; }
-
-        /// <inheritdoc />
-        public IDictionary<string, RenderAsyncDelegate> PreviousSectionWriters { get; set; }
-
         protected override HtmlEncoder Encoder => HtmlEncoder;
 
         /// <summary>
@@ -289,7 +291,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor
         }
 
         /// <inheritdoc />
-        public void EnsureRenderedBodyOrSections()
+        public override void EnsureRenderedBodyOrSections()
         {
             // a) all sections defined for this page are rendered.
             // b) if no sections are defined, then the body is rendered if it's available.
@@ -324,6 +326,10 @@ namespace Microsoft.AspNetCore.Mvc.Razor
             }
         }
 
+        // Working around an issue with ApiCheck tool
+        /// <inheritdoc />
+        public override Task<HtmlString> FlushAsync() => base.FlushAsync();
+
         public override void BeginContext(int position, int length, bool isLiteral)
         {
             const string BeginContextEvent = "Microsoft.AspNetCore.Mvc.Razor.BeginInstrumentationContext";
diff --git a/src/Microsoft.AspNetCore.Mvc.Razor/RazorPageBase.cs b/src/Microsoft.AspNetCore.Mvc.Razor/RazorPageBase.cs
index 9f852567a7..89255284bc 100644
--- a/src/Microsoft.AspNetCore.Mvc.Razor/RazorPageBase.cs
+++ b/src/Microsoft.AspNetCore.Mvc.Razor/RazorPageBase.cs
@@ -22,7 +22,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor
     /// <summary>
     /// Represents properties and methods that are needed in order to render a view that uses Razor syntax.
     /// </summary>
-    public abstract class RazorPageBase
+    public abstract class RazorPageBase : IRazorPage
     {
         private StringWriter _valueBuffer;
         private ITagHelperFactory _tagHelperFactory;
@@ -73,8 +73,15 @@ namespace Microsoft.AspNetCore.Mvc.Razor
         /// </summary>
         public dynamic ViewBag => ViewContext?.ViewBag;
 
+        /// <inheritdoc />
         public bool IsLayoutBeingRendered { get; set; }
 
+        /// <inheritdoc />
+        public IHtmlContent BodyContent { get; set; }
+
+        /// <inheritdoc />
+        public IDictionary<string, RenderAsyncDelegate> PreviousSectionWriters { get; set; }
+
         protected virtual HtmlEncoder Encoder { get; set; }
 
         protected Stack<TagHelperScopeInfo> TagHelperScopes { get; } = new Stack<TagHelperScopeInfo>();
@@ -714,6 +721,8 @@ namespace Microsoft.AspNetCore.Mvc.Razor
                 (value is bool && (bool)value);
         }
 
+        public abstract void EnsureRenderedBodyOrSections();
+
         private struct AttributeInfo
         {
             public AttributeInfo(
diff --git a/src/Microsoft.AspNetCore.Mvc.RazorPages/Page.cs b/src/Microsoft.AspNetCore.Mvc.RazorPages/Page.cs
index 02d3e43077..488fd0ac70 100644
--- a/src/Microsoft.AspNetCore.Mvc.RazorPages/Page.cs
+++ b/src/Microsoft.AspNetCore.Mvc.RazorPages/Page.cs
@@ -21,12 +21,6 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages
         private IUrlHelper _urlHelper;
         private PageArgumentBinder _binder;
 
-        /// <inheritdoc />
-        public IHtmlContent BodyContent { get; set; }
-
-        /// <inheritdoc />
-        public IDictionary<string, RenderAsyncDelegate> PreviousSectionWriters { get; set; }
-
         /// <summary>
         /// The <see cref="PageContext"/>.
         /// </summary>
@@ -73,9 +67,9 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages
         }
 
         /// <inheritdoc />
-        public void EnsureRenderedBodyOrSections()
+        public override void EnsureRenderedBodyOrSections()
         {
-            throw new NotImplementedException();
+            throw new NotSupportedException();
         }
 
         public override void BeginContext(int position, int length, bool isLiteral)