diff --git a/src/BizHawk.Client.EmuHawk/tools/MultiDiskBundler/MultiDiskBundler.cs b/src/BizHawk.Client.EmuHawk/tools/MultiDiskBundler/MultiDiskBundler.cs
index f44c4b43be..a16029c246 100644
--- a/src/BizHawk.Client.EmuHawk/tools/MultiDiskBundler/MultiDiskBundler.cs
+++ b/src/BizHawk.Client.EmuHawk/tools/MultiDiskBundler/MultiDiskBundler.cs
@@ -214,7 +214,7 @@ namespace BizHawk.Client.EmuHawk
 					new XElement("LoadAssets",
 						names.Select(n => new XElement(
 							"Asset",
-							new XAttribute("FileName", GetRelativePath(basePath, n))
+							new XAttribute("FileName", PathExtensions.GetRelativePath(basePath, n))
 						))
 					)
 				);
@@ -270,36 +270,6 @@ namespace BizHawk.Client.EmuHawk
 			}
 		}
 
-		/// <exception cref="ArgumentException">running on Windows host, and unmanaged call failed</exception>
-		/// <exception cref="FileNotFoundException">running on Windows host, and either path is not a regular file or directory</exception>
-		/// <remarks>Algorithm for Windows taken from https://stackoverflow.com/a/485516/7467292</remarks>
-		public static string GetRelativePath(string fromPath, string toPath)
-		{
-			if (OSTailoredCode.IsUnixHost) return fromPath.MakeRelativeTo(toPath);
-
-			//TODO merge this with the Windows implementation in PathExtensions.MakeRelativeTo
-			static FileAttributes GetPathAttribute(string path1)
-			{
-				var di = new DirectoryInfo(path1.Split('|').First());
-				if (di.Exists)
-				{
-					return FileAttributes.Directory;
-				}
-
-				var fi = new FileInfo(path1.Split('|').First());
-				if (fi.Exists)
-				{
-					return FileAttributes.Normal;
-				}
-
-				throw new FileNotFoundException();
-			}
-			var path = new StringBuilder(260 /* = MAX_PATH */);
-			return Win32Imports.PathRelativePathTo(path, fromPath, GetPathAttribute(fromPath), toPath, GetPathAttribute(toPath))
-				? path.ToString()
-				: throw new ArgumentException("Paths must have a common prefix");
-		}
-
 		private void SystemDropDown_SelectedIndexChanged(object sender, EventArgs e)
 		{
 			Recalculate();
diff --git a/src/BizHawk.Common/Extensions/PathExtensions.cs b/src/BizHawk.Common/Extensions/PathExtensions.cs
index 8c09d34e87..6c644d89cd 100644
--- a/src/BizHawk.Common/Extensions/PathExtensions.cs
+++ b/src/BizHawk.Common/Extensions/PathExtensions.cs
@@ -1,6 +1,8 @@
 using System;
+using System.Text;
 using System.IO;
 using System.Reflection;
+using System.Linq;
 
 using BizHawk.Common.StringExtensions;
 
@@ -45,6 +47,36 @@ namespace BizHawk.Common.PathExtensions
 			return false;
 		}
 
+	/// <exception cref="ArgumentException">running on Windows host, and unmanaged call failed</exception>
+		/// <exception cref="FileNotFoundException">running on Windows host, and either path is not a regular file or directory</exception>
+		/// <remarks>Algorithm for Windows taken from https://stackoverflow.com/a/485516/7467292</remarks>
+		public static string GetRelativePath(string fromPath, string toPath)
+		{
+			if (OSTailoredCode.IsUnixHost) return fromPath.MakeRelativeTo(toPath);
+
+			//TODO merge this with the Windows implementation in PathExtensions.MakeRelativeTo
+			static FileAttributes GetPathAttribute(string path1)
+			{
+				var di = new DirectoryInfo(path1.Split('|').First());
+				if (di.Exists)
+				{
+					return FileAttributes.Directory;
+				}
+
+				var fi = new FileInfo(path1.Split('|').First());
+				if (fi.Exists)
+				{
+					return FileAttributes.Normal;
+				}
+
+				throw new FileNotFoundException();
+			}
+			var path = new StringBuilder(260 /* = MAX_PATH */);
+			return Win32Imports.PathRelativePathTo(path, fromPath, GetPathAttribute(fromPath), toPath, GetPathAttribute(toPath))
+				? path.ToString()
+				: throw new ArgumentException("Paths must have a common prefix");
+		}
+
 		/// <returns>the absolute path equivalent to <paramref name="path"/> which contains <c>%exe%</c> (expanded) as a prefix</returns>
 		/// <remarks>
 		/// returned string omits trailing slash<br/>