diff --git a/src/Gtk/Perspex.Gtk/Input/GtkKeyboardDevice.cs b/src/Gtk/Perspex.Gtk/Input/GtkKeyboardDevice.cs
index 3ccec97656..b0b9016ff6 100644
--- a/src/Gtk/Perspex.Gtk/Input/GtkKeyboardDevice.cs
+++ b/src/Gtk/Perspex.Gtk/Input/GtkKeyboardDevice.cs
@@ -214,7 +214,7 @@ namespace Perspex.Gtk
             //{ Gdk.Key.?, Key.DeadCharProcessed }
         };
 
-        public static GtkKeyboardDevice Instance { get; } = new GtkKeyboardDevice();
+        public new static GtkKeyboardDevice Instance { get; } = new GtkKeyboardDevice();
 
         public static Key ConvertKey(Gdk.Key key)
         {
diff --git a/src/Markup/Perspex.Markup/Data/ExpressionNodeBuilder.cs b/src/Markup/Perspex.Markup/Data/ExpressionNodeBuilder.cs
index af70bc717e..93b38a438a 100644
--- a/src/Markup/Perspex.Markup/Data/ExpressionNodeBuilder.cs
+++ b/src/Markup/Perspex.Markup/Data/ExpressionNodeBuilder.cs
@@ -20,7 +20,7 @@ namespace Perspex.Markup.Data
 
             if (!reader.End)
             {
-                throw new ExpressionParseException(reader, "Expected end of expression.");
+                throw new ExpressionParseException(reader.Position, "Expected end of expression.");
             }
 
             return node;
diff --git a/src/Markup/Perspex.Markup/Data/ExpressionParseException.cs b/src/Markup/Perspex.Markup/Data/ExpressionParseException.cs
index fffeac8a77..d92f42cab7 100644
--- a/src/Markup/Perspex.Markup/Data/ExpressionParseException.cs
+++ b/src/Markup/Perspex.Markup/Data/ExpressionParseException.cs
@@ -6,19 +6,26 @@ using Perspex.Markup.Data.Parsers;
 
 namespace Perspex.Markup.Data
 {
+    /// <summary>
+    /// Exception thrown when <see cref="ExpressionObserver"/> could not parse the provided
+    /// expression string.
+    /// </summary>
     public class ExpressionParseException : Exception
     {
-        internal ExpressionParseException(int column, string message)
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ExpressionParseException"/> class.
+        /// </summary>
+        /// <param name="column">The column position of the error.</param>
+        /// <param name="message">The exception message.</param>
+        public ExpressionParseException(int column, string message)
             : base(message)
         {
             Column = column;
         }
 
-        internal ExpressionParseException(Reader r, string message)
-            : this(r.Position, message)
-        {
-        }
-
+        /// <summary>
+        /// Gets the column position at which the error occurred.
+        /// </summary>
         public int Column { get; }
     }
 }
diff --git a/src/Markup/Perspex.Markup/Data/Parsers/ArgumentListParser.cs b/src/Markup/Perspex.Markup/Data/Parsers/ArgumentListParser.cs
index 588e3257b5..5b67166739 100644
--- a/src/Markup/Perspex.Markup/Data/Parsers/ArgumentListParser.cs
+++ b/src/Markup/Perspex.Markup/Data/Parsers/ArgumentListParser.cs
@@ -26,14 +26,14 @@ namespace Perspex.Markup.Data.Parsers
                     }
                     else
                     {
-                        throw new ExpressionParseException(r, "Expected integer.");
+                        throw new ExpressionParseException(r.Position, "Expected integer.");
                     }
 
                     r.SkipWhitespace();
 
                     if (r.End)
                     {
-                        throw new ExpressionParseException(r, "Expected ','.");
+                        throw new ExpressionParseException(r.Position, "Expected ','.");
                     }
                     else if (r.TakeIf(close))
                     {
@@ -43,7 +43,7 @@ namespace Perspex.Markup.Data.Parsers
                     {
                         if (r.Take() != ',')
                         {
-                            throw new ExpressionParseException(r, "Expected ','.");
+                            throw new ExpressionParseException(r.Position, "Expected ','.");
                         }
 
                         r.SkipWhitespace();
@@ -57,7 +57,7 @@ namespace Perspex.Markup.Data.Parsers
                 }
                 else
                 {
-                    throw new ExpressionParseException(r, "Expected ']'.");
+                    throw new ExpressionParseException(r.Position, "Expected ']'.");
                 }
             }
 
diff --git a/src/Markup/Perspex.Markup/Data/Parsers/ExpressionParser.cs b/src/Markup/Perspex.Markup/Data/Parsers/ExpressionParser.cs
index 6f743175c9..2ec7f49f5c 100644
--- a/src/Markup/Perspex.Markup/Data/Parsers/ExpressionParser.cs
+++ b/src/Markup/Perspex.Markup/Data/Parsers/ExpressionParser.cs
@@ -34,7 +34,7 @@ namespace Perspex.Markup.Data.Parsers
 
             if (state == State.BeforeMember)
             {
-                throw new ExpressionParseException(r, "Unexpected end of expression.");
+                throw new ExpressionParseException(r.Position, "Unexpected end of expression.");
             }
 
             for (int n = 0; n < nodes.Count - 1; ++n)
@@ -80,7 +80,7 @@ namespace Perspex.Markup.Data.Parsers
                 {
                     if (args.Count == 0)
                     {
-                        throw new ExpressionParseException(r, "Indexer may not be empty.");
+                        throw new ExpressionParseException(r.Position, "Indexer may not be empty.");
                     }
 
                     nodes.Add(new IndexerNode(args));
diff --git a/src/Perspex.Base/Threading/DispatcherTimer.cs b/src/Perspex.Base/Threading/DispatcherTimer.cs
index d84bcf519e..18eedff08f 100644
--- a/src/Perspex.Base/Threading/DispatcherTimer.cs
+++ b/src/Perspex.Base/Threading/DispatcherTimer.cs
@@ -31,7 +31,6 @@ namespace Perspex.Threading
         /// Initializes a new instance of the <see cref="DispatcherTimer"/> class.
         /// </summary>
         /// <param name="priority">The priority to use.</param>
-        /// <param name="dispatcher">The dispatcher to use.</param>
         public DispatcherTimer(DispatcherPriority priority)
         {
             _priority = priority;
@@ -43,7 +42,6 @@ namespace Perspex.Threading
         /// </summary>
         /// <param name="interval">The interval at which to tick.</param>
         /// <param name="priority">The priority to use.</param>
-        /// <param name="dispatcher">The dispatcher to use.</param>
         /// <param name="callback">The event to call when the timer ticks.</param>
         public DispatcherTimer(TimeSpan interval, DispatcherPriority priority, EventHandler callback) : this(priority)
         {
diff --git a/src/Perspex.SceneGraph/Platform/IPlatformRenderInterface.cs b/src/Perspex.SceneGraph/Platform/IPlatformRenderInterface.cs
index ccf55104a8..244c3bc335 100644
--- a/src/Perspex.SceneGraph/Platform/IPlatformRenderInterface.cs
+++ b/src/Perspex.SceneGraph/Platform/IPlatformRenderInterface.cs
@@ -39,8 +39,6 @@ namespace Perspex.Platform
         /// Creates a renderer.
         /// </summary>
         /// <param name="handle">The platform handle for the renderer.</param>
-        /// <param name="width">The initial width of the render.</param>
-        /// <param name="height">The initial height of the render.</param>
         /// <returns>An <see cref="IRenderTarget"/>.</returns>
         IRenderTarget CreateRenderer(IPlatformHandle handle);
 
diff --git a/src/Perspex.Styling/Styling/Selectors.cs b/src/Perspex.Styling/Styling/Selectors.cs
index d291bcd3f9..65f0d6dee0 100644
--- a/src/Perspex.Styling/Styling/Selectors.cs
+++ b/src/Perspex.Styling/Styling/Selectors.cs
@@ -131,7 +131,6 @@ namespace Perspex.Styling
         /// <summary>
         /// Returns a selector which matches a control with the specified property value.
         /// </summary>
-        /// <typeparam name="T">The property type.</typeparam>
         /// <param name="previous">The previous selector.</param>
         /// <param name="property">The property.</param>
         /// <param name="value">The property value.</param>
diff --git a/src/Skia/Perspex.Skia/BitmapImpl.cs b/src/Skia/Perspex.Skia/BitmapImpl.cs
index 75c2ae5213..83d89feac0 100644
--- a/src/Skia/Perspex.Skia/BitmapImpl.cs
+++ b/src/Skia/Perspex.Skia/BitmapImpl.cs
@@ -10,9 +10,6 @@ namespace Perspex.Skia
 {
     class BitmapImpl : PerspexHandleHolder, IRenderTargetBitmapImpl
     {
-        private int width;
-        private int height;
-
         public void Save(string fileName)
         {
             var ext = Path.GetExtension(fileName)?.ToLower();
diff --git a/src/Windows/Perspex.Direct2D1/Media/TileBrushImpl.cs b/src/Windows/Perspex.Direct2D1/Media/TileBrushImpl.cs
index 0f0d929b9e..413035f5e9 100644
--- a/src/Windows/Perspex.Direct2D1/Media/TileBrushImpl.cs
+++ b/src/Windows/Perspex.Direct2D1/Media/TileBrushImpl.cs
@@ -36,7 +36,7 @@ namespace Perspex.Direct2D1.Media
         }
 
 
-        protected static BrushProperties GetBrushProperties(TileBrush brush, Rect destinationRect)
+        private static BrushProperties GetBrushProperties(TileBrush brush, Rect destinationRect)
         {
             return new BrushProperties
             {
@@ -49,7 +49,7 @@ namespace Perspex.Direct2D1.Media
             };
         }
 
-        protected static BitmapBrushProperties GetBitmapBrushProperties(TileBrush brush)
+        private static BitmapBrushProperties GetBitmapBrushProperties(TileBrush brush)
         {
             var tileMode = brush.TileMode;
 
@@ -60,12 +60,12 @@ namespace Perspex.Direct2D1.Media
             };
         }
 
-        protected static ExtendMode GetExtendModeX(TileMode tileMode)
+        private static ExtendMode GetExtendModeX(TileMode tileMode)
         {
             return (tileMode & TileMode.FlipX) != 0 ? ExtendMode.Mirror : ExtendMode.Wrap;
         }
 
-        protected static ExtendMode GetExtendModeY(TileMode tileMode)
+        private static ExtendMode GetExtendModeY(TileMode tileMode)
         {
             return (tileMode & TileMode.FlipY) != 0 ? ExtendMode.Mirror : ExtendMode.Wrap;
         }
diff --git a/src/Windows/Perspex.Direct2D1/RenderTarget.cs b/src/Windows/Perspex.Direct2D1/RenderTarget.cs
index 53a04683d2..9627f25053 100644
--- a/src/Windows/Perspex.Direct2D1/RenderTarget.cs
+++ b/src/Windows/Perspex.Direct2D1/RenderTarget.cs
@@ -30,8 +30,6 @@ namespace Perspex.Direct2D1
         /// Initializes a new instance of the <see cref="RenderTarget"/> class.
         /// </summary>
         /// <param name="hwnd">The window handle.</param>
-        /// <param name="width">The width of the window.</param>
-        /// <param name="height">The height of the window.</param>
         public RenderTarget(IntPtr hwnd)
         {
             _hwnd = hwnd;
diff --git a/src/Windows/Perspex.Win32/Input/WindowsKeyboardDevice.cs b/src/Windows/Perspex.Win32/Input/WindowsKeyboardDevice.cs
index 10598c4e00..34935f5e82 100644
--- a/src/Windows/Perspex.Win32/Input/WindowsKeyboardDevice.cs
+++ b/src/Windows/Perspex.Win32/Input/WindowsKeyboardDevice.cs
@@ -10,11 +10,9 @@ namespace Perspex.Win32.Input
 {
     public class WindowsKeyboardDevice : KeyboardDevice
     {
-        private static readonly WindowsKeyboardDevice s_instance = new WindowsKeyboardDevice();
-
         private readonly byte[] _keyStates = new byte[256];
 
-        public static new WindowsKeyboardDevice Instance => s_instance;
+        public new static WindowsKeyboardDevice Instance { get; } = new WindowsKeyboardDevice();
 
         public InputModifiers Modifiers
         {
diff --git a/src/Windows/Perspex.Win32/Interop/UnmanagedMethods.cs b/src/Windows/Perspex.Win32/Interop/UnmanagedMethods.cs
index 80dd0cd672..3c7154e480 100644
--- a/src/Windows/Perspex.Win32/Interop/UnmanagedMethods.cs
+++ b/src/Windows/Perspex.Win32/Interop/UnmanagedMethods.cs
@@ -7,7 +7,7 @@ using System.Runtime.InteropServices;
 using System.Text;
 
 // ReSharper disable InconsistentNaming
-#pragma warning disable 169
+#pragma warning disable 169, 649
 
 namespace Perspex.Win32.Interop
 {
diff --git a/tests/Perspex.Interactivity.UnitTests/InteractiveTests.cs b/tests/Perspex.Interactivity.UnitTests/InteractiveTests.cs
index 156fa05fce..3a3d47947a 100644
--- a/tests/Perspex.Interactivity.UnitTests/InteractiveTests.cs
+++ b/tests/Perspex.Interactivity.UnitTests/InteractiveTests.cs
@@ -338,8 +338,6 @@ namespace Perspex.Interactivity.UnitTests
 
         private class TestInteractive : Interactive
         {
-            public string Name { get; set; }
-
             public bool ClassHandlerInvoked { get; private set; }
 
             public IEnumerable<IVisual> Children