diff --git a/SafeExamBrowser.Configuration/Bounds.cs b/SafeExamBrowser.Configuration/Bounds.cs
new file mode 100644
index 00000000..ce83b546
--- /dev/null
+++ b/SafeExamBrowser.Configuration/Bounds.cs
@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2017 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using SafeExamBrowser.Contracts.WindowsApi;
+
+namespace SafeExamBrowser.Configuration
+{
+	internal class Bounds : IBounds
+	{
+		public int Left { get; set; }
+		public int Top { get; set; }
+		public int Right { get; set; }
+		public int Bottom { get; set; }
+	}
+}
diff --git a/SafeExamBrowser.Configuration/SafeExamBrowser.Configuration.csproj b/SafeExamBrowser.Configuration/SafeExamBrowser.Configuration.csproj
index ef19d3db..86d1dbd6 100644
--- a/SafeExamBrowser.Configuration/SafeExamBrowser.Configuration.csproj
+++ b/SafeExamBrowser.Configuration/SafeExamBrowser.Configuration.csproj
@@ -60,6 +60,7 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Bounds.cs" />
     <Compile Include="Settings\BrowserSettings.cs" />
     <Compile Include="Settings\SettingsImpl.cs" />
     <Compile Include="WorkingArea.cs" />
diff --git a/SafeExamBrowser.Configuration/WorkingArea.cs b/SafeExamBrowser.Configuration/WorkingArea.cs
index 804b1b03..00f8d00c 100644
--- a/SafeExamBrowser.Configuration/WorkingArea.cs
+++ b/SafeExamBrowser.Configuration/WorkingArea.cs
@@ -11,7 +11,6 @@ using SafeExamBrowser.Contracts.Configuration;
 using SafeExamBrowser.Contracts.Logging;
 using SafeExamBrowser.Contracts.UserInterface;
 using SafeExamBrowser.Contracts.WindowsApi;
-using SafeExamBrowser.Contracts.WindowsApi.Types;
 
 namespace SafeExamBrowser.Configuration
 {
@@ -19,7 +18,7 @@ namespace SafeExamBrowser.Configuration
 	{
 		private ILogger logger;
 		private INativeMethods nativeMethods;
-		private RECT? originalWorkingArea;
+		private IBounds originalWorkingArea;
 
 		public WorkingArea(ILogger logger, INativeMethods nativeMethods)
 		{
@@ -31,9 +30,9 @@ namespace SafeExamBrowser.Configuration
 		{
 			originalWorkingArea = nativeMethods.GetWorkingArea();
 
-			LogWorkingArea("Saved original working area", originalWorkingArea.Value);
+			LogWorkingArea("Saved original working area", originalWorkingArea);
 
-			var area = new RECT
+			var area = new Bounds
 			{
 				Left = 0,
 				Top = 0,
@@ -48,14 +47,14 @@ namespace SafeExamBrowser.Configuration
 
 		public void Reset()
 		{
-			if (originalWorkingArea.HasValue)
+			if (originalWorkingArea != null)
 			{
-				nativeMethods.SetWorkingArea(originalWorkingArea.Value);
-				LogWorkingArea("Restored original working area", originalWorkingArea.Value);
+				nativeMethods.SetWorkingArea(originalWorkingArea);
+				LogWorkingArea("Restored original working area", originalWorkingArea);
 			}
 		}
 
-		private void LogWorkingArea(string message, RECT area)
+		private void LogWorkingArea(string message, IBounds area)
 		{
 			logger.Info($"{message}: Left = {area.Left}, Top = {area.Top}, Right = {area.Right}, Bottom = {area.Bottom}.");
 		}
diff --git a/SafeExamBrowser.Contracts/SafeExamBrowser.Contracts.csproj b/SafeExamBrowser.Contracts/SafeExamBrowser.Contracts.csproj
index 1d43922c..b0065bd9 100644
--- a/SafeExamBrowser.Contracts/SafeExamBrowser.Contracts.csproj
+++ b/SafeExamBrowser.Contracts/SafeExamBrowser.Contracts.csproj
@@ -98,8 +98,8 @@
     <Compile Include="UserInterface\IWindow.cs" />
     <Compile Include="UserInterface\MessageBoxAction.cs" />
     <Compile Include="UserInterface\MessageBoxIcon.cs" />
+    <Compile Include="WindowsApi\IBounds.cs" />
     <Compile Include="WindowsApi\INativeMethods.cs" />
-    <Compile Include="WindowsApi\Types\RECT.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
 </Project>
\ No newline at end of file
diff --git a/SafeExamBrowser.Contracts/WindowsApi/IBounds.cs b/SafeExamBrowser.Contracts/WindowsApi/IBounds.cs
new file mode 100644
index 00000000..6816f241
--- /dev/null
+++ b/SafeExamBrowser.Contracts/WindowsApi/IBounds.cs
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2017 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+namespace SafeExamBrowser.Contracts.WindowsApi
+{
+	public interface IBounds
+	{
+		int Left { get; }
+		int Top { get; }
+		int Right { get; }
+		int Bottom { get; }
+	}
+}
diff --git a/SafeExamBrowser.Contracts/WindowsApi/INativeMethods.cs b/SafeExamBrowser.Contracts/WindowsApi/INativeMethods.cs
index a139d49b..8cd0145c 100644
--- a/SafeExamBrowser.Contracts/WindowsApi/INativeMethods.cs
+++ b/SafeExamBrowser.Contracts/WindowsApi/INativeMethods.cs
@@ -9,7 +9,6 @@
 using System;
 using System.Collections.Generic;
 using SafeExamBrowser.Contracts.Monitoring;
-using SafeExamBrowser.Contracts.WindowsApi.Types;
 
 namespace SafeExamBrowser.Contracts.WindowsApi
 {
@@ -52,7 +51,7 @@ namespace SafeExamBrowser.Contracts.WindowsApi
 		/// <exception cref="System.ComponentModel.Win32Exception">
 		/// If the working area could not be retrieved.
 		/// </exception>
-		RECT GetWorkingArea();
+		IBounds GetWorkingArea();
 
 		/// <summary>
 		/// Hides the given window. Returns <c>true</c> if successful, otherwise <c>false</c>.
@@ -105,7 +104,7 @@ namespace SafeExamBrowser.Contracts.WindowsApi
 		/// <exception cref="System.ComponentModel.Win32Exception">
 		/// If the working area could not be set.
 		/// </exception>
-		void SetWorkingArea(RECT bounds);
+		void SetWorkingArea(IBounds bounds);
 
 		/// <summary>
 		/// Unregisters the system hook for the given keyboard interceptor.
diff --git a/SafeExamBrowser.WindowsApi/Monitoring/KeyboardHook.cs b/SafeExamBrowser.WindowsApi/Monitoring/KeyboardHook.cs
index bc6a5312..ea18acdf 100644
--- a/SafeExamBrowser.WindowsApi/Monitoring/KeyboardHook.cs
+++ b/SafeExamBrowser.WindowsApi/Monitoring/KeyboardHook.cs
@@ -10,6 +10,7 @@ using System;
 using System.Runtime.InteropServices;
 using SafeExamBrowser.Contracts.Monitoring;
 using SafeExamBrowser.WindowsApi.Constants;
+using SafeExamBrowser.WindowsApi.Types;
 
 namespace SafeExamBrowser.WindowsApi.Monitoring
 {
diff --git a/SafeExamBrowser.WindowsApi/NativeMethods.cs b/SafeExamBrowser.WindowsApi/NativeMethods.cs
index 4c942b3f..d6792052 100644
--- a/SafeExamBrowser.WindowsApi/NativeMethods.cs
+++ b/SafeExamBrowser.WindowsApi/NativeMethods.cs
@@ -15,9 +15,9 @@ using System.Runtime.InteropServices;
 using System.Text;
 using SafeExamBrowser.Contracts.Monitoring;
 using SafeExamBrowser.Contracts.WindowsApi;
-using SafeExamBrowser.Contracts.WindowsApi.Types;
 using SafeExamBrowser.WindowsApi.Constants;
 using SafeExamBrowser.WindowsApi.Monitoring;
+using SafeExamBrowser.WindowsApi.Types;
 
 namespace SafeExamBrowser.WindowsApi
 {
@@ -99,7 +99,7 @@ namespace SafeExamBrowser.WindowsApi
 			return string.Empty;
 		}
 
-		public RECT GetWorkingArea()
+		public IBounds GetWorkingArea()
 		{
 			var workingArea = new RECT();
 			var success = User32.SystemParametersInfo(SPI.GETWORKAREA, 0, ref workingArea, SPIF.NONE);
@@ -109,7 +109,7 @@ namespace SafeExamBrowser.WindowsApi
 				throw new Win32Exception(Marshal.GetLastWin32Error());
 			}
 
-			return workingArea;
+			return workingArea.ToBounds();
 		}
 
 		public bool HideWindow(IntPtr window)
@@ -194,9 +194,10 @@ namespace SafeExamBrowser.WindowsApi
 			User32.SendMessage(window, Constant.WM_SYSCOMMAND, (IntPtr) SystemCommand.CLOSE, IntPtr.Zero);
 		}
 
-		public void SetWorkingArea(RECT bounds)
+		public void SetWorkingArea(IBounds bounds)
 		{
-			var success = User32.SystemParametersInfo(SPI.SETWORKAREA, 0, ref bounds, SPIF.UPDATEANDCHANGE);
+			var workingArea = new RECT { Left = bounds.Left, Top = bounds.Top, Right = bounds.Right, Bottom = bounds.Bottom };
+			var success = User32.SystemParametersInfo(SPI.SETWORKAREA, 0, ref workingArea, SPIF.UPDATEANDCHANGE);
 
 			if (!success)
 			{
diff --git a/SafeExamBrowser.WindowsApi/SafeExamBrowser.WindowsApi.csproj b/SafeExamBrowser.WindowsApi/SafeExamBrowser.WindowsApi.csproj
index 05670949..f7476236 100644
--- a/SafeExamBrowser.WindowsApi/SafeExamBrowser.WindowsApi.csproj
+++ b/SafeExamBrowser.WindowsApi/SafeExamBrowser.WindowsApi.csproj
@@ -60,8 +60,9 @@
   <ItemGroup>
     <Compile Include="Constants\Constant.cs" />
     <Compile Include="Constants\HookType.cs" />
-    <Compile Include="Constants\KBDLLHOOKSTRUCT.cs" />
-    <Compile Include="Constants\KBDLLHOOKSTRUCTFlags.cs" />
+    <Compile Include="Types\Bounds.cs" />
+    <Compile Include="Types\KBDLLHOOKSTRUCT.cs" />
+    <Compile Include="Types\KBDLLHOOKSTRUCTFlags.cs" />
     <Compile Include="Constants\ShowWindowCommand.cs" />
     <Compile Include="Constants\SystemCommand.cs" />
     <Compile Include="Kernel32.cs" />
@@ -70,6 +71,7 @@
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Constants\SPI.cs" />
     <Compile Include="Constants\SPIF.cs" />
+    <Compile Include="Types\RECT.cs" />
     <Compile Include="User32.cs" />
   </ItemGroup>
   <ItemGroup>
diff --git a/SafeExamBrowser.WindowsApi/Types/Bounds.cs b/SafeExamBrowser.WindowsApi/Types/Bounds.cs
new file mode 100644
index 00000000..b9d3b44a
--- /dev/null
+++ b/SafeExamBrowser.WindowsApi/Types/Bounds.cs
@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2017 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using SafeExamBrowser.Contracts.WindowsApi;
+
+namespace SafeExamBrowser.WindowsApi.Types
+{
+	internal class Bounds : IBounds
+	{
+		public int Left { get; set; }
+		public int Top { get; set; }
+		public int Right { get; set; }
+		public int Bottom { get; set; }
+	}
+}
diff --git a/SafeExamBrowser.WindowsApi/Constants/KBDLLHOOKSTRUCT.cs b/SafeExamBrowser.WindowsApi/Types/KBDLLHOOKSTRUCT.cs
similarity index 97%
rename from SafeExamBrowser.WindowsApi/Constants/KBDLLHOOKSTRUCT.cs
rename to SafeExamBrowser.WindowsApi/Types/KBDLLHOOKSTRUCT.cs
index 4568b295..06fb3cc2 100644
--- a/SafeExamBrowser.WindowsApi/Constants/KBDLLHOOKSTRUCT.cs
+++ b/SafeExamBrowser.WindowsApi/Types/KBDLLHOOKSTRUCT.cs
@@ -9,7 +9,7 @@
 using System;
 using System.Runtime.InteropServices;
 
-namespace SafeExamBrowser.WindowsApi.Constants
+namespace SafeExamBrowser.WindowsApi.Types
 {
 	/// <remarks>
 	/// See http://www.pinvoke.net/default.aspx/Structures/KBDLLHOOKSTRUCT.html.
diff --git a/SafeExamBrowser.WindowsApi/Constants/KBDLLHOOKSTRUCTFlags.cs b/SafeExamBrowser.WindowsApi/Types/KBDLLHOOKSTRUCTFlags.cs
similarity index 94%
rename from SafeExamBrowser.WindowsApi/Constants/KBDLLHOOKSTRUCTFlags.cs
rename to SafeExamBrowser.WindowsApi/Types/KBDLLHOOKSTRUCTFlags.cs
index a4e07b0b..0e38ac8f 100644
--- a/SafeExamBrowser.WindowsApi/Constants/KBDLLHOOKSTRUCTFlags.cs
+++ b/SafeExamBrowser.WindowsApi/Types/KBDLLHOOKSTRUCTFlags.cs
@@ -6,7 +6,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-namespace SafeExamBrowser.WindowsApi.Constants
+namespace SafeExamBrowser.WindowsApi.Types
 {
 	/// <remarks>
 	/// See http://www.pinvoke.net/default.aspx/Structures/KBDLLHOOKSTRUCT.html.
diff --git a/SafeExamBrowser.Contracts/WindowsApi/Types/RECT.cs b/SafeExamBrowser.WindowsApi/Types/RECT.cs
similarity index 60%
rename from SafeExamBrowser.Contracts/WindowsApi/Types/RECT.cs
rename to SafeExamBrowser.WindowsApi/Types/RECT.cs
index 7b883657..c520e253 100644
--- a/SafeExamBrowser.Contracts/WindowsApi/Types/RECT.cs
+++ b/SafeExamBrowser.WindowsApi/Types/RECT.cs
@@ -7,18 +7,30 @@
  */
 
 using System.Runtime.InteropServices;
+using SafeExamBrowser.Contracts.WindowsApi;
 
-namespace SafeExamBrowser.Contracts.WindowsApi.Types
+namespace SafeExamBrowser.WindowsApi.Types
 {
 	/// <summary>
 	/// See https://msdn.microsoft.com/en-us/library/windows/desktop/dd162897(v=vs.85).aspx.
 	/// </summary>
 	[StructLayout(LayoutKind.Sequential)]
-	public struct RECT
+	internal struct RECT
 	{
-		public int Left;
-		public int Top;
-		public int Right;
-		public int Bottom;
+		internal int Left;
+		internal int Top;
+		internal int Right;
+		internal int Bottom;
+
+		internal IBounds ToBounds()
+		{
+			return new Bounds
+			{
+				Left = Left,
+				Top = Top,
+				Right = Right,
+				Bottom = Bottom
+			};
+		}
 	}
 }
diff --git a/SafeExamBrowser.WindowsApi/User32.cs b/SafeExamBrowser.WindowsApi/User32.cs
index 4a37ed18..0d6f5ed2 100644
--- a/SafeExamBrowser.WindowsApi/User32.cs
+++ b/SafeExamBrowser.WindowsApi/User32.cs
@@ -9,8 +9,8 @@
 using System;
 using System.Runtime.InteropServices;
 using System.Text;
-using SafeExamBrowser.Contracts.WindowsApi.Types;
 using SafeExamBrowser.WindowsApi.Constants;
+using SafeExamBrowser.WindowsApi.Types;
 
 namespace SafeExamBrowser.WindowsApi
 {