diff --git a/src/Umbraco.Core/IO/ShadowFileSystem.cs b/src/Umbraco.Core/IO/ShadowFileSystem.cs
index faf3678495..bce8b8861b 100644
--- a/src/Umbraco.Core/IO/ShadowFileSystem.cs
+++ b/src/Umbraco.Core/IO/ShadowFileSystem.cs
@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Text.RegularExpressions;
 
 namespace Umbraco.Core.IO
 {
@@ -209,10 +210,11 @@ namespace Umbraco.Core.IO
             var normPath = NormPath(path);
             var shadows = Nodes.Where(kvp => IsChild(normPath, kvp.Key)).ToArray();
             var files = filter != null ? _fs.GetFiles(path, filter) : _fs.GetFiles(path);
+            var regexFilter = FilterToRegex(filter);
             return files
                 .Except(shadows.Where(kvp => (kvp.Value.IsFile && kvp.Value.IsDelete) || kvp.Value.IsDir)
                     .Select(kvp => kvp.Key))
-                .Union(shadows.Where(kvp => kvp.Value.IsFile && kvp.Value.IsExist).Select(kvp => kvp.Key))
+                .Union(shadows.Where(kvp => kvp.Value.IsFile && kvp.Value.IsExist && FilterByRegex(kvp.Key, regexFilter)).Select(kvp => kvp.Key))
                 .Distinct();
         }
 
@@ -285,5 +287,32 @@ namespace Umbraco.Core.IO
             if (sf.IsDelete || sf.IsDir) throw new InvalidOperationException("Invalid path.");
             return _sfs.GetSize(path);
         }
+
+        /// <summary>
+        /// Helper function for filtering keys by Regex if a filter is specified.
+        /// </summary>
+        /// <param name="input"></param>
+        /// <param name="regexFilter"></param>
+        /// <returns></returns>
+        internal static bool FilterByRegex(string input, string regexFilter)
+        {
+            if (regexFilter == null) return true;
+            return regexFilter != string.Empty && Regex.IsMatch(input, regexFilter);
+        }
+
+        /// <summary>
+        /// Transforms a filter pattern into a Regex pattern
+        /// </summary>
+        /// <param name="pattern"></param>
+        /// <returns></returns>
+        /// <remarks>
+        /// Appending '$' only if not containing wildcard is stupid and broken.
+        /// It is however what seems to be what they're doing in .NET so we need to match the functionality.
+        /// </remarks>
+        internal static string FilterToRegex(string pattern)
+        {
+            if (pattern == null) return null;
+            return "^" + Regex.Escape(pattern).Replace("\\*", ".*").Replace("\\?", ".") + (pattern.Contains("*") ? string.Empty : "$");
+        }
     }
 }
diff --git a/src/Umbraco.Tests/IO/ShadowFileSystemTests.cs b/src/Umbraco.Tests/IO/ShadowFileSystemTests.cs
index 85a2ae3345..ac4a25385d 100644
--- a/src/Umbraco.Tests/IO/ShadowFileSystemTests.cs
+++ b/src/Umbraco.Tests/IO/ShadowFileSystemTests.cs
@@ -650,8 +650,6 @@ namespace Umbraco.Tests.IO
             // ensure we get 2 files from the shadow
             var getFiles = ss.GetFiles(string.Empty);
             Assert.AreEqual(2, getFiles.Count());
-            var getFilesWithFilter = ss.GetFiles(string.Empty, "*");
-            Assert.AreEqual(2, getFilesWithFilter.Count());
             
             var fsFiles = fs.GetFiles(string.Empty).ToArray();
             Assert.AreEqual(1, fsFiles.Length);
@@ -659,6 +657,241 @@ namespace Umbraco.Tests.IO
             Assert.AreEqual(1, sfsFiles.Length);
         }
 
+        /// <summary>
+        /// Check that GetFiles using the filter function with empty string will return expected results
+        /// </summary>
+        [Test]
+        public void ShadowGetFilesUsingEmptyFilter()
+        {
+            // Arrange
+            var path = IOHelper.MapPath("FileSysTests");
+            Directory.CreateDirectory(path);
+            Directory.CreateDirectory(path + "/ShadowTests");
+            Directory.CreateDirectory(path + "/ShadowSystem");
+
+            var fs = new PhysicalFileSystem(path + "/ShadowTests/", "ignore");
+            var sfs = new PhysicalFileSystem(path + "/ShadowSystem/", "ignore");
+            var ss = new ShadowFileSystem(fs, sfs);
+
+            // Act
+            File.WriteAllText(path + "/ShadowTests/f2.txt", "foo");
+            using (var ms = new MemoryStream(Encoding.UTF8.GetBytes("foo")))
+                ss.AddFile("f1.txt", ms);
+
+            // Assert
+            // ensure we get 2 files from the shadow
+            var getFiles = ss.GetFiles(string.Empty);
+            Assert.AreEqual(2, getFiles.Count());
+            // ensure we get 0 files when using a empty filter
+            var getFilesWithEmptyFilter = ss.GetFiles(string.Empty, "");
+            Assert.AreEqual(0, getFilesWithEmptyFilter.Count());
+
+            var fsFiles = fs.GetFiles(string.Empty).ToArray();
+            Assert.AreEqual(1, fsFiles.Length);
+            var sfsFiles = sfs.GetFiles(string.Empty).ToArray();
+            Assert.AreEqual(1, sfsFiles.Length);
+        }
+
+        /// <summary>
+        /// Check that GetFiles using the filter function with null will return expected results
+        /// </summary>
+        [Test]
+        public void ShadowGetFilesUsingNullFilter()
+        {
+            // Arrange
+            var path = IOHelper.MapPath("FileSysTests");
+            Directory.CreateDirectory(path);
+            Directory.CreateDirectory(path + "/ShadowTests");
+            Directory.CreateDirectory(path + "/ShadowSystem");
+
+            var fs = new PhysicalFileSystem(path + "/ShadowTests/", "ignore");
+            var sfs = new PhysicalFileSystem(path + "/ShadowSystem/", "ignore");
+            var ss = new ShadowFileSystem(fs, sfs);
+
+            // Act
+            File.WriteAllText(path + "/ShadowTests/f2.txt", "foo");
+            using (var ms = new MemoryStream(Encoding.UTF8.GetBytes("foo")))
+                ss.AddFile("f1.txt", ms);
+
+            // Assert
+            // ensure we get 2 files from the shadow
+            var getFiles = ss.GetFiles(string.Empty);
+            Assert.AreEqual(2, getFiles.Count());
+            // ensure we get 2 files when using null in filter parameter
+            var getFilesWithNullFilter = ss.GetFiles(string.Empty, null);
+            Assert.AreEqual(2, getFilesWithNullFilter.Count());
+
+            var fsFiles = fs.GetFiles(string.Empty).ToArray();
+            Assert.AreEqual(1, fsFiles.Length);
+            var sfsFiles = sfs.GetFiles(string.Empty).ToArray();
+            Assert.AreEqual(1, sfsFiles.Length);
+        }
+
+        [Test]
+        public void ShadowGetFilesUsingWildcardFilter()
+        {
+            // Arrange
+            var path = IOHelper.MapPath("FileSysTests");
+            Directory.CreateDirectory(path);
+            Directory.CreateDirectory(path + "/ShadowTests");
+            Directory.CreateDirectory(path + "/ShadowSystem");
+
+            var fs = new PhysicalFileSystem(path + "/ShadowTests/", "ignore");
+            var sfs = new PhysicalFileSystem(path + "/ShadowSystem/", "ignore");
+            var ss = new ShadowFileSystem(fs, sfs);
+
+            // Act
+            File.WriteAllText(path + "/ShadowTests/f2.txt", "foo");
+            File.WriteAllText(path + "/ShadowTests/f2.doc", "foo");
+            using (var ms = new MemoryStream(Encoding.UTF8.GetBytes("foo")))
+                ss.AddFile("f1.txt", ms);
+            using (var ms = new MemoryStream(Encoding.UTF8.GetBytes("foo")))
+                ss.AddFile("f1.doc", ms);
+
+            // Assert
+            // ensure we get 4 files from the shadow
+            var getFiles = ss.GetFiles(string.Empty);
+            Assert.AreEqual(4, getFiles.Count());
+            // ensure we get only 2 of 4 files from the shadow when using filter
+            var getFilesWithWildcardFilter = ss.GetFiles(string.Empty, "*.doc");
+            Assert.AreEqual(2, getFilesWithWildcardFilter.Count());
+
+            var fsFiles = fs.GetFiles(string.Empty).ToArray();
+            Assert.AreEqual(2, fsFiles.Length);
+            var sfsFiles = sfs.GetFiles(string.Empty).ToArray();
+            Assert.AreEqual(2, sfsFiles.Length);
+        }
+
+        [Test]
+        public void ShadowGetFilesUsingSingleCharacterFilter()
+        {
+            // Arrange
+            var path = IOHelper.MapPath("FileSysTests");
+            Directory.CreateDirectory(path);
+            Directory.CreateDirectory(path + "/ShadowTests");
+            Directory.CreateDirectory(path + "/ShadowSystem");
+
+            var fs = new PhysicalFileSystem(path + "/ShadowTests/", "ignore");
+            var sfs = new PhysicalFileSystem(path + "/ShadowSystem/", "ignore");
+            var ss = new ShadowFileSystem(fs, sfs);
+
+            // Act
+            File.WriteAllText(path + "/ShadowTests/f2.txt", "foo");
+            File.WriteAllText(path + "/ShadowTests/f2.doc", "foo");
+            File.WriteAllText(path + "/ShadowTests/f2.docx", "foo");
+            using (var ms = new MemoryStream(Encoding.UTF8.GetBytes("foo")))
+                ss.AddFile("f1.txt", ms);
+            using (var ms = new MemoryStream(Encoding.UTF8.GetBytes("foo")))
+                ss.AddFile("f1.doc", ms);
+            using (var ms = new MemoryStream(Encoding.UTF8.GetBytes("foo")))
+                ss.AddFile("f1.docx", ms);
+
+            // Assert
+            // ensure we get 6 files from the shadow
+            var getFiles = ss.GetFiles(string.Empty);
+            Assert.AreEqual(6, getFiles.Count());
+            // ensure we get only 2 of 6 files from the shadow when using filter on shadow
+            var getFilesWithWildcardSinglecharFilter = ss.GetFiles(string.Empty, "f1.d?c");
+            Assert.AreEqual(1, getFilesWithWildcardSinglecharFilter.Count());
+            // ensure we get only 2 of 6 files from the shadow when using filter on disk
+            var getFilesWithWildcardSinglecharFilter2 = ss.GetFiles(string.Empty, "f2.d?c");
+            Assert.AreEqual(1, getFilesWithWildcardSinglecharFilter2.Count());
+
+            var fsFiles = fs.GetFiles(string.Empty).ToArray();
+            Assert.AreEqual(3, fsFiles.Length);
+            var sfsFiles = sfs.GetFiles(string.Empty).ToArray();
+            Assert.AreEqual(3, sfsFiles.Length);
+        }
+
+        [Test]
+        public void ShadowGetFilesUsingWildcardAndSingleCharacterFilter()
+        {
+            // Arrange
+            var path = IOHelper.MapPath("FileSysTests");
+            Directory.CreateDirectory(path);
+            Directory.CreateDirectory(path + "/ShadowTests");
+            Directory.CreateDirectory(path + "/ShadowSystem");
+
+            var fs = new PhysicalFileSystem(path + "/ShadowTests/", "ignore");
+            var sfs = new PhysicalFileSystem(path + "/ShadowSystem/", "ignore");
+            var ss = new ShadowFileSystem(fs, sfs);
+
+            // Act
+            File.WriteAllText(path + "/ShadowTests/f2.txt", "foo");
+            File.WriteAllText(path + "/ShadowTests/f2.doc", "foo");
+            File.WriteAllText(path + "/ShadowTests/f2.docx", "foo");
+            using (var ms = new MemoryStream(Encoding.UTF8.GetBytes("foo")))
+                ss.AddFile("f1.txt", ms);
+            using (var ms = new MemoryStream(Encoding.UTF8.GetBytes("foo")))
+                ss.AddFile("f1.doc", ms);
+            using (var ms = new MemoryStream(Encoding.UTF8.GetBytes("foo")))
+                ss.AddFile("f1.docx", ms);
+
+            // Assert
+            // ensure we get 6 files from the shadow
+            var getFiles = ss.GetFiles(string.Empty);
+            Assert.AreEqual(6, getFiles.Count());
+            var getFilesWithWildcardSinglecharFilter = ss.GetFiles(string.Empty, "*.d?c");
+
+            Assert.AreEqual(4, getFilesWithWildcardSinglecharFilter.Count());
+            var getFilesWithWildcardSinglecharFilter2 = ss.GetFiles(string.Empty, "*.d?cx");
+            Assert.AreEqual(2, getFilesWithWildcardSinglecharFilter2.Count());
+
+            var fsFiles = fs.GetFiles(string.Empty).ToArray();
+            Assert.AreEqual(3, fsFiles.Length);
+            var sfsFiles = sfs.GetFiles(string.Empty).ToArray();
+            Assert.AreEqual(3, sfsFiles.Length);
+        }
+
+        [Test]
+        public void ShadowFileSystemFilterIsAsBrokenAsRealFileSystemFilter()
+        {
+            // Arrange
+            var path = IOHelper.MapPath("FileSysTests");
+            Directory.CreateDirectory(path);
+            Directory.CreateDirectory(path + "/filter");
+            // create files on disk and create a "fake" list of files to verify filters against
+            File.WriteAllText(path + "/filter/f1.txt", "foo");
+            File.WriteAllText(path + "/filter/f1.doc", "foo");
+            File.WriteAllText(path + "/filter/f1.docx", "foo");
+            var files = new string[]
+            {
+                "f1.txt",
+                "f1.doc",
+                "f1.docx",
+            };
+            var filter1 = "";
+            var filter2 = "*";
+            var filter3 = "*.doc";
+            var filter4 = "*.d?c";
+            var filter5 = "f1.doc";
+            var filter6 = "f1.d?c";
+            var filter7 = "**.d?c";
+
+            // Act & Assert
+            var result1Disk = Directory.GetFiles(path + "/filter/", filter1).Select(Path.GetFileName).OrderBy(x => x).ToArray();
+            var result1Fake = files.Where(x => ShadowFileSystem.FilterByRegex(x, ShadowFileSystem.FilterToRegex(filter1))).OrderBy(x => x).ToArray();
+            Assert.AreEqual(result1Disk, result1Fake);
+            var result2Disk = Directory.GetFiles(path + "/filter/", filter2).Select(Path.GetFileName).OrderBy(x => x).ToArray();
+            var result2Fake = files.Where(x => ShadowFileSystem.FilterByRegex(x, ShadowFileSystem.FilterToRegex(filter2))).OrderBy(x => x).ToArray();
+            Assert.AreEqual(result2Disk, result2Fake);
+            var result3Disk = Directory.GetFiles(path + "/filter/", filter3).Select(Path.GetFileName).OrderBy(x => x).ToArray();
+            var result3Fake = files.Where(x => ShadowFileSystem.FilterByRegex(x, ShadowFileSystem.FilterToRegex(filter3))).OrderBy(x => x).ToArray();
+            Assert.AreEqual(result3Disk, result3Fake);
+            var result4Disk = Directory.GetFiles(path + "/filter/", filter4).Select(Path.GetFileName).OrderBy(x => x).ToArray();
+            var result4Fake = files.Where(x => ShadowFileSystem.FilterByRegex(x, ShadowFileSystem.FilterToRegex(filter4))).OrderBy(x => x).ToArray();
+            Assert.AreEqual(result4Disk, result4Fake);
+            var result5Disk = Directory.GetFiles(path + "/filter/", filter5).Select(Path.GetFileName).OrderBy(x => x).ToArray();
+            var result5Fake = files.Where(x => ShadowFileSystem.FilterByRegex(x, ShadowFileSystem.FilterToRegex(filter5))).OrderBy(x => x).ToArray();
+            Assert.AreEqual(result5Disk, result5Fake);
+            var result6Disk = Directory.GetFiles(path + "/filter/", filter6).Select(Path.GetFileName).OrderBy(x => x).ToArray();
+            var result6Fake = files.Where(x => ShadowFileSystem.FilterByRegex(x, ShadowFileSystem.FilterToRegex(filter6))).OrderBy(x => x).ToArray();
+            Assert.AreEqual(result6Disk, result6Fake);
+            var result7Disk = Directory.GetFiles(path + "/filter/", filter7).Select(Path.GetFileName).OrderBy(x => x).ToArray();
+            var result7Fake = files.Where(x => ShadowFileSystem.FilterByRegex(x, ShadowFileSystem.FilterToRegex(filter7))).OrderBy(x => x).ToArray();
+            Assert.AreEqual(result7Disk, result7Fake);
+        }
+
         /// <summary>
         /// Returns the full paths of the files on the disk.
         /// Note that this will be the *actual* path of the file, meaning a file existing on the initialized FS