diff --git a/src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFile.cs b/src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFile.cs
index 0f9a97a48..e4d739704 100644
--- a/src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFile.cs
+++ b/src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFile.cs
@@ -677,7 +677,7 @@ private FileSystemStream OpenInternal(
         }
         mockFileDataAccessor.AdjustTimes(mockFileData, timeAdjustments);
 
-        return new MockFileStream(mockFileDataAccessor, path, mode, access, options);
+        return new MockFileStream(mockFileDataAccessor, path, mode, access, FileShare.Read, options);
     }
 
     /// <inheritdoc />
diff --git a/src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFileStream.cs b/src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFileStream.cs
index 1be2241af..05ab473f5 100644
--- a/src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFileStream.cs
+++ b/src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFileStream.cs
@@ -2,6 +2,7 @@
 using System.Threading;
 using System.Runtime.Versioning;
 using System.Security.AccessControl;
+using System.Collections.Concurrent;
 
 namespace System.IO.Abstractions.TestingHelpers;
 
@@ -32,9 +33,11 @@ public NullFileSystemStream() : base(Null, ".", true)
     private readonly IMockFileDataAccessor mockFileDataAccessor;
     private readonly string path;
     private readonly FileAccess access = FileAccess.ReadWrite;
+    private readonly FileShare share = FileShare.Read;
     private readonly FileOptions options;
     private readonly MockFileData fileData;
     private bool disposed;
+    private static ConcurrentDictionary<string, byte> _fileShareNoneStreams = [];
 
     /// <inheritdoc />
     public MockFileStream(
@@ -42,6 +45,7 @@ public MockFileStream(
         string path,
         FileMode mode,
         FileAccess access = FileAccess.ReadWrite,
+        FileShare share = FileShare.Read,
         FileOptions options = FileOptions.None)
         : base(new MemoryStream(),
             path == null ? null : Path.GetFullPath(path),
@@ -51,9 +55,15 @@ public MockFileStream(
         ThrowIfInvalidModeAccess(mode, access);
 
         this.mockFileDataAccessor = mockFileDataAccessor ?? throw new ArgumentNullException(nameof(mockFileDataAccessor));
+        path = mockFileDataAccessor.PathVerifier.FixPath(path);
         this.path = path;
         this.options = options;
 
+        if (_fileShareNoneStreams.ContainsKey(path)) 
+        {
+            throw CommonExceptions.ProcessCannotAccessFileInUse(path);
+        }
+
         if (mockFileDataAccessor.FileExists(path))
         {
             if (mode.Equals(FileMode.CreateNew))
@@ -97,7 +107,15 @@ public MockFileStream(
             mockFileDataAccessor.AddFile(path, fileData);
         }
 
+        if (share is FileShare.None) 
+        {
+            if (!_fileShareNoneStreams.TryAdd(path, 0))
+            {
+                throw CommonExceptions.ProcessCannotAccessFileInUse(path);
+            }
+        }
         this.access = access;
+        this.share = share;
     }
 
     private static void ThrowIfInvalidModeAccess(FileMode mode, FileAccess access)
@@ -144,6 +162,10 @@ protected override void Dispose(bool disposing)
         {
             return;
         }
+        if (share is FileShare.None)
+        {
+            _fileShareNoneStreams.TryRemove(path, out _);
+        }
         InternalFlush();
         base.Dispose(disposing);
         OnClose();
diff --git a/src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFileStreamFactory.cs b/src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFileStreamFactory.cs
index 9cd34f7ae..1dc39759c 100644
--- a/src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFileStreamFactory.cs
+++ b/src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFileStreamFactory.cs
@@ -41,25 +41,25 @@ public FileSystemStream New(string path, FileMode mode, FileAccess access)
 
     /// <inheritdoc />
     public FileSystemStream New(string path, FileMode mode, FileAccess access, FileShare share)
-        => new MockFileStream(mockFileSystem, path, mode, access);
+        => new MockFileStream(mockFileSystem, path, mode, access, share);
 
     /// <inheritdoc />
     public FileSystemStream New(string path, FileMode mode, FileAccess access, FileShare share, int bufferSize)
-        => new MockFileStream(mockFileSystem, path, mode, access);
+        => new MockFileStream(mockFileSystem, path, mode, access, share);
 
     /// <inheritdoc />
     public FileSystemStream New(string path, FileMode mode, FileAccess access, FileShare share, int bufferSize, bool useAsync)
-        => new MockFileStream(mockFileSystem, path, mode, access);
+        => new MockFileStream(mockFileSystem, path, mode, access, share);
 
     /// <inheritdoc />
     public FileSystemStream New(string path, FileMode mode, FileAccess access, FileShare share, int bufferSize,
         FileOptions options)
-        => new MockFileStream(mockFileSystem, path, mode, access, options);
+        => new MockFileStream(mockFileSystem, path, mode, access, share, options);
 
 #if FEATURE_FILESTREAM_OPTIONS
     /// <inheritdoc />
     public FileSystemStream New(string path, FileStreamOptions options)
-        => new MockFileStream(mockFileSystem, path, options.Mode, options.Access, options.Options);
+        => new MockFileStream(mockFileSystem, path, options.Mode, options.Access, options.Share, options.Options);
 #endif
 
     /// <inheritdoc />
diff --git a/src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFileSystem.cs b/src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFileSystem.cs
index 3f71206cb..34b809c21 100644
--- a/src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFileSystem.cs
+++ b/src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFileSystem.cs
@@ -128,19 +128,6 @@ public MockFileSystem MockTime(Func<DateTime> dateTimeProvider)
         return this;
     }
 
-    private string FixPath(string path, bool checkCaps = false)
-    {
-        if (path == null)
-        {
-            throw new ArgumentNullException(nameof(path), StringResources.Manager.GetString("VALUE_CANNOT_BE_NULL"));
-        }
-
-        var pathSeparatorFixed = path.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar);
-        var fullPath = Path.GetFullPath(pathSeparatorFixed);
-
-        return checkCaps ? GetPathWithCorrectDirectoryCapitalization(fullPath) : fullPath;
-    }
-
     //If C:\foo exists, ensures that trying to save a file to "C:\FOO\file.txt" instead saves it to "C:\foo\file.txt".
     private string GetPathWithCorrectDirectoryCapitalization(string fullPath)
     {
@@ -194,7 +181,7 @@ public MockFileData AdjustTimes(MockFileData fileData, TimeAdjustments timeAdjus
     /// <inheritdoc />
     public MockFileData GetFile(string path)
     {
-        path = FixPath(path).TrimSlashes();
+        path = pathVerifier.FixPath(path).TrimSlashes();
         return GetFileWithoutFixingPath(path);
     }
 
@@ -210,7 +197,9 @@ public MockDriveData GetDrive(string name)
 
     private void SetEntry(string path, MockFileData mockFile)
     {
-        path = FixPath(path, true).TrimSlashes();
+        path = GetPathWithCorrectDirectoryCapitalization(
+            pathVerifier.FixPath(path)
+        ).TrimSlashes();
 
         lock (files)
         {
@@ -232,7 +221,9 @@ private void SetEntry(string path, MockFileData mockFile)
     /// <inheritdoc />
     public void AddFile(string path, MockFileData mockFile, bool verifyAccess = true)
     {
-        var fixedPath = FixPath(path, true);
+        var fixedPath = GetPathWithCorrectDirectoryCapitalization(
+            pathVerifier.FixPath(path)
+        );
 
         mockFile ??= new MockFileData(string.Empty);
         var file = GetFile(fixedPath);
@@ -319,7 +310,9 @@ public MockFileData GetFile(IFileInfo path)
     /// <inheritdoc />
     public void AddDirectory(string path)
     {
-        var fixedPath = FixPath(path, true);
+        var fixedPath = GetPathWithCorrectDirectoryCapitalization(
+            pathVerifier.FixPath(path)
+        );
         var separator = Path.DirectorySeparatorChar.ToString();
 
         if (FileExists(fixedPath) && FileIsReadOnly(fixedPath))
@@ -408,8 +401,8 @@ public void AddDrive(string name, MockDriveData mockDrive)
     /// <inheritdoc />
     public void MoveDirectory(string sourcePath, string destPath)
     {
-        sourcePath = FixPath(sourcePath);
-        destPath = FixPath(destPath);
+        sourcePath = pathVerifier.FixPath(sourcePath);
+        destPath = pathVerifier.FixPath(destPath);
 
         var sourcePathSequence = sourcePath.Split(new[] { Path.DirectorySeparatorChar }, StringSplitOptions.RemoveEmptyEntries);
 
@@ -452,7 +445,7 @@ bool PathStartsWith(string path, string[] minMatch)
     /// <inheritdoc />
     public void RemoveFile(string path, bool verifyAccess = true)
     {
-        path = FixPath(path);
+        path = pathVerifier.FixPath(path);
 
         lock (files)
         {
@@ -473,7 +466,7 @@ public bool FileExists(string path)
             return false;
         }
 
-        path = FixPath(path).TrimSlashes();
+        path = pathVerifier.FixPath(path).TrimSlashes();
 
         lock (files)
         {
diff --git a/src/TestableIO.System.IO.Abstractions.TestingHelpers/PathVerifier.cs b/src/TestableIO.System.IO.Abstractions.TestingHelpers/PathVerifier.cs
index 2c426637c..93405eebb 100644
--- a/src/TestableIO.System.IO.Abstractions.TestingHelpers/PathVerifier.cs
+++ b/src/TestableIO.System.IO.Abstractions.TestingHelpers/PathVerifier.cs
@@ -183,4 +183,23 @@ public bool TryNormalizeDriveName(string name, out string result)
         result = name;
         return true;
     }
+
+    /// <summary>
+    /// Resolves and normalizes a path.
+    /// </summary>
+    public string FixPath(string path)
+    {
+        if (path == null)
+        {
+            throw new ArgumentNullException(nameof(path), StringResources.Manager.GetString("VALUE_CANNOT_BE_NULL"));
+        }
+
+        var pathSeparatorFixed = path.Replace(
+            _mockFileDataAccessor.Path.AltDirectorySeparatorChar,
+            _mockFileDataAccessor.Path.DirectorySeparatorChar
+        );
+        var fullPath = _mockFileDataAccessor.Path.GetFullPath(pathSeparatorFixed);
+
+        return fullPath;
+    }
 }
diff --git a/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net472.txt b/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net472.txt
index 788ddb703..094f901ae 100644
--- a/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net472.txt
+++ b/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net472.txt
@@ -297,7 +297,7 @@ namespace System.IO.Abstractions.TestingHelpers
     [System.Serializable]
     public class MockFileStream : System.IO.Abstractions.FileSystemStream, System.IO.Abstractions.IFileSystemAclSupport
     {
-        public MockFileStream(System.IO.Abstractions.TestingHelpers.IMockFileDataAccessor mockFileDataAccessor, string path, System.IO.FileMode mode, System.IO.FileAccess access = 3, System.IO.FileOptions options = 0) { }
+        public MockFileStream(System.IO.Abstractions.TestingHelpers.IMockFileDataAccessor mockFileDataAccessor, string path, System.IO.FileMode mode, System.IO.FileAccess access = 3, System.IO.FileShare share = 1, System.IO.FileOptions options = 0) { }
         public override bool CanRead { get; }
         public override bool CanWrite { get; }
         public static System.IO.Abstractions.FileSystemStream Null { get; }
@@ -468,6 +468,7 @@ namespace System.IO.Abstractions.TestingHelpers
     {
         public PathVerifier(System.IO.Abstractions.TestingHelpers.IMockFileDataAccessor mockFileDataAccessor) { }
         public void CheckInvalidPathChars(string path, bool checkAdditional = false) { }
+        public string FixPath(string path) { }
         public bool HasIllegalCharacters(string path, bool checkAdditional) { }
         public void IsLegalAbsoluteOrRelative(string path, string paramName) { }
         public string NormalizeDriveName(string name) { }
diff --git a/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net6.0.txt b/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net6.0.txt
index afd2ce3c4..d8dcd5d80 100644
--- a/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net6.0.txt
+++ b/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net6.0.txt
@@ -346,7 +346,7 @@ namespace System.IO.Abstractions.TestingHelpers
     [System.Serializable]
     public class MockFileStream : System.IO.Abstractions.FileSystemStream, System.IO.Abstractions.IFileSystemAclSupport
     {
-        public MockFileStream(System.IO.Abstractions.TestingHelpers.IMockFileDataAccessor mockFileDataAccessor, string path, System.IO.FileMode mode, System.IO.FileAccess access = 3, System.IO.FileOptions options = 0) { }
+        public MockFileStream(System.IO.Abstractions.TestingHelpers.IMockFileDataAccessor mockFileDataAccessor, string path, System.IO.FileMode mode, System.IO.FileAccess access = 3, System.IO.FileShare share = 1, System.IO.FileOptions options = 0) { }
         public override bool CanRead { get; }
         public override bool CanWrite { get; }
         public static System.IO.Abstractions.FileSystemStream Null { get; }
@@ -524,6 +524,7 @@ namespace System.IO.Abstractions.TestingHelpers
     {
         public PathVerifier(System.IO.Abstractions.TestingHelpers.IMockFileDataAccessor mockFileDataAccessor) { }
         public void CheckInvalidPathChars(string path, bool checkAdditional = false) { }
+        public string FixPath(string path) { }
         public bool HasIllegalCharacters(string path, bool checkAdditional) { }
         public void IsLegalAbsoluteOrRelative(string path, string paramName) { }
         public string NormalizeDriveName(string name) { }
diff --git a/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net8.0.txt b/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net8.0.txt
index 1c581cab8..d5d7baa8e 100644
--- a/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net8.0.txt
+++ b/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net8.0.txt
@@ -370,7 +370,7 @@ namespace System.IO.Abstractions.TestingHelpers
     [System.Serializable]
     public class MockFileStream : System.IO.Abstractions.FileSystemStream, System.IO.Abstractions.IFileSystemAclSupport
     {
-        public MockFileStream(System.IO.Abstractions.TestingHelpers.IMockFileDataAccessor mockFileDataAccessor, string path, System.IO.FileMode mode, System.IO.FileAccess access = 3, System.IO.FileOptions options = 0) { }
+        public MockFileStream(System.IO.Abstractions.TestingHelpers.IMockFileDataAccessor mockFileDataAccessor, string path, System.IO.FileMode mode, System.IO.FileAccess access = 3, System.IO.FileShare share = 1, System.IO.FileOptions options = 0) { }
         public override bool CanRead { get; }
         public override bool CanWrite { get; }
         public static System.IO.Abstractions.FileSystemStream Null { get; }
@@ -549,6 +549,7 @@ namespace System.IO.Abstractions.TestingHelpers
     {
         public PathVerifier(System.IO.Abstractions.TestingHelpers.IMockFileDataAccessor mockFileDataAccessor) { }
         public void CheckInvalidPathChars(string path, bool checkAdditional = false) { }
+        public string FixPath(string path) { }
         public bool HasIllegalCharacters(string path, bool checkAdditional) { }
         public void IsLegalAbsoluteOrRelative(string path, string paramName) { }
         public string NormalizeDriveName(string name) { }
diff --git a/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net9.0.txt b/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net9.0.txt
index 6c78cf677..b59eb5dbc 100644
--- a/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net9.0.txt
+++ b/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net9.0.txt
@@ -384,7 +384,7 @@ namespace System.IO.Abstractions.TestingHelpers
     [System.Serializable]
     public class MockFileStream : System.IO.Abstractions.FileSystemStream, System.IO.Abstractions.IFileSystemAclSupport
     {
-        public MockFileStream(System.IO.Abstractions.TestingHelpers.IMockFileDataAccessor mockFileDataAccessor, string path, System.IO.FileMode mode, System.IO.FileAccess access = 3, System.IO.FileOptions options = 0) { }
+        public MockFileStream(System.IO.Abstractions.TestingHelpers.IMockFileDataAccessor mockFileDataAccessor, string path, System.IO.FileMode mode, System.IO.FileAccess access = 3, System.IO.FileShare share = 1, System.IO.FileOptions options = 0) { }
         public override bool CanRead { get; }
         public override bool CanWrite { get; }
         public static System.IO.Abstractions.FileSystemStream Null { get; }
@@ -563,6 +563,7 @@ namespace System.IO.Abstractions.TestingHelpers
     {
         public PathVerifier(System.IO.Abstractions.TestingHelpers.IMockFileDataAccessor mockFileDataAccessor) { }
         public void CheckInvalidPathChars(string path, bool checkAdditional = false) { }
+        public string FixPath(string path) { }
         public bool HasIllegalCharacters(string path, bool checkAdditional) { }
         public void IsLegalAbsoluteOrRelative(string path, string paramName) { }
         public string NormalizeDriveName(string name) { }
diff --git a/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_netstandard2.0.txt b/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_netstandard2.0.txt
index e0880b9f8..39357be50 100644
--- a/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_netstandard2.0.txt
+++ b/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_netstandard2.0.txt
@@ -297,7 +297,7 @@ namespace System.IO.Abstractions.TestingHelpers
     [System.Serializable]
     public class MockFileStream : System.IO.Abstractions.FileSystemStream, System.IO.Abstractions.IFileSystemAclSupport
     {
-        public MockFileStream(System.IO.Abstractions.TestingHelpers.IMockFileDataAccessor mockFileDataAccessor, string path, System.IO.FileMode mode, System.IO.FileAccess access = 3, System.IO.FileOptions options = 0) { }
+        public MockFileStream(System.IO.Abstractions.TestingHelpers.IMockFileDataAccessor mockFileDataAccessor, string path, System.IO.FileMode mode, System.IO.FileAccess access = 3, System.IO.FileShare share = 1, System.IO.FileOptions options = 0) { }
         public override bool CanRead { get; }
         public override bool CanWrite { get; }
         public static System.IO.Abstractions.FileSystemStream Null { get; }
@@ -468,6 +468,7 @@ namespace System.IO.Abstractions.TestingHelpers
     {
         public PathVerifier(System.IO.Abstractions.TestingHelpers.IMockFileDataAccessor mockFileDataAccessor) { }
         public void CheckInvalidPathChars(string path, bool checkAdditional = false) { }
+        public string FixPath(string path) { }
         public bool HasIllegalCharacters(string path, bool checkAdditional) { }
         public void IsLegalAbsoluteOrRelative(string path, string paramName) { }
         public string NormalizeDriveName(string name) { }
diff --git a/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_netstandard2.1.txt b/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_netstandard2.1.txt
index 80f876c0c..df8c9c634 100644
--- a/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_netstandard2.1.txt
+++ b/tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_netstandard2.1.txt
@@ -323,7 +323,7 @@ namespace System.IO.Abstractions.TestingHelpers
     [System.Serializable]
     public class MockFileStream : System.IO.Abstractions.FileSystemStream, System.IO.Abstractions.IFileSystemAclSupport
     {
-        public MockFileStream(System.IO.Abstractions.TestingHelpers.IMockFileDataAccessor mockFileDataAccessor, string path, System.IO.FileMode mode, System.IO.FileAccess access = 3, System.IO.FileOptions options = 0) { }
+        public MockFileStream(System.IO.Abstractions.TestingHelpers.IMockFileDataAccessor mockFileDataAccessor, string path, System.IO.FileMode mode, System.IO.FileAccess access = 3, System.IO.FileShare share = 1, System.IO.FileOptions options = 0) { }
         public override bool CanRead { get; }
         public override bool CanWrite { get; }
         public static System.IO.Abstractions.FileSystemStream Null { get; }
@@ -497,6 +497,7 @@ namespace System.IO.Abstractions.TestingHelpers
     {
         public PathVerifier(System.IO.Abstractions.TestingHelpers.IMockFileDataAccessor mockFileDataAccessor) { }
         public void CheckInvalidPathChars(string path, bool checkAdditional = false) { }
+        public string FixPath(string path) { }
         public bool HasIllegalCharacters(string path, bool checkAdditional) { }
         public void IsLegalAbsoluteOrRelative(string path, string paramName) { }
         public string NormalizeDriveName(string name) { }
diff --git a/tests/TestableIO.System.IO.Abstractions.TestingHelpers.Tests/MockFileStreamTests.cs b/tests/TestableIO.System.IO.Abstractions.TestingHelpers.Tests/MockFileStreamTests.cs
index b82566d9a..f973c1732 100644
--- a/tests/TestableIO.System.IO.Abstractions.TestingHelpers.Tests/MockFileStreamTests.cs
+++ b/tests/TestableIO.System.IO.Abstractions.TestingHelpers.Tests/MockFileStreamTests.cs
@@ -390,4 +390,26 @@ async Task Act() =>
             await source.CopyToAsync(destination);
         await That(Act).Throws<NotSupportedException>();
     }
+
+    [Test]
+    public async Task MockFileStream_WhenExclusiveStreamOpen_ShouldThrowIOException()
+    {
+        var fileSystem = new MockFileSystem();
+        fileSystem.File.WriteAllText("foo.txt", "");
+        using (new MockFileStream(fileSystem, "foo.txt", FileMode.Open, FileAccess.Read, FileShare.None))
+        {
+            await That(() => new MockFileStream(fileSystem, "foo.txt", FileMode.Open, FileAccess.Read)).Throws<IOException>();
+        }
+    }
+
+    [Test]
+    public async Task MockFileStream_WhenExclusiveStreamClosed_ShouldNotThrow()
+    {
+        var fileSystem = new MockFileSystem();
+        fileSystem.File.WriteAllText("foo.txt", "");
+        var stream = new MockFileStream(fileSystem, "foo.txt", FileMode.Open, FileAccess.Read, FileShare.None);
+        stream.Dispose();
+
+        await That(() => new MockFileStream(fileSystem, "foo.txt", FileMode.Open, FileAccess.Read)).DoesNotThrow();
+    }
 }
\ No newline at end of file