diff --git a/Directory.Build.props b/Directory.Build.props
index 0f3335b8f..ed4f6a281 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -5,6 +5,8 @@
     <Authors>Tatham Oddie &amp; friends</Authors>
     <SignAssembly Condition="'$(Configuration)' == 'Release'">True</SignAssembly>
     <AssemblyOriginatorKeyFile>$(MSBuildThisFileDirectory)StrongName.snk</AssemblyOriginatorKeyFile>
+    <DefineConstants Condition="'$(TargetFramework)' == 'netcoreapp3.0' OR '$(TargetFramework)' == 'netstandard2.1'">$(DefineConstants);FEATURE_ASYNC_FILE;FEATURE_ENUMERATION_OPTIONS;FEATURE_ADVANCED_PATH_OPERATIONS</DefineConstants>
+
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Nerdbank.GitVersioning" Version="3.0.50">
diff --git a/System.IO.Abstractions.TestingHelpers.Tests/MockPathTests.cs b/System.IO.Abstractions.TestingHelpers.Tests/MockPathTests.cs
index 3c59d6646..d66fb281b 100644
--- a/System.IO.Abstractions.TestingHelpers.Tests/MockPathTests.cs
+++ b/System.IO.Abstractions.TestingHelpers.Tests/MockPathTests.cs
@@ -143,13 +143,13 @@ public static IEnumerable<string[]> GetFullPath_RelativePaths_Cases
         {
             get
             {
-                yield return new [] { XFS.Path(@"c:\a"), "b", XFS.Path(@"c:\a\b") };
-                yield return new [] { XFS.Path(@"c:\a\b"), "c", XFS.Path(@"c:\a\b\c") };
-                yield return new [] { XFS.Path(@"c:\a\b"), XFS.Path(@"c\"), XFS.Path(@"c:\a\b\c\") };
-                yield return new [] { XFS.Path(@"c:\a\b"), XFS.Path(@"..\c"), XFS.Path(@"c:\a\c") };
-                yield return new [] { XFS.Path(@"c:\a\b\c"), XFS.Path(@"..\c\..\"), XFS.Path(@"c:\a\b\") };
-                yield return new [] { XFS.Path(@"c:\a\b\c"), XFS.Path(@"..\..\..\..\..\d"), XFS.Path(@"c:\d") };
-                yield return new [] { XFS.Path(@"c:\a\b\c"), XFS.Path(@"..\..\..\..\..\d\"), XFS.Path(@"c:\d\") };
+                yield return new[] { XFS.Path(@"c:\a"), "b", XFS.Path(@"c:\a\b") };
+                yield return new[] { XFS.Path(@"c:\a\b"), "c", XFS.Path(@"c:\a\b\c") };
+                yield return new[] { XFS.Path(@"c:\a\b"), XFS.Path(@"c\"), XFS.Path(@"c:\a\b\c\") };
+                yield return new[] { XFS.Path(@"c:\a\b"), XFS.Path(@"..\c"), XFS.Path(@"c:\a\c") };
+                yield return new[] { XFS.Path(@"c:\a\b\c"), XFS.Path(@"..\c\..\"), XFS.Path(@"c:\a\b\") };
+                yield return new[] { XFS.Path(@"c:\a\b\c"), XFS.Path(@"..\..\..\..\..\d"), XFS.Path(@"c:\d") };
+                yield return new[] { XFS.Path(@"c:\a\b\c"), XFS.Path(@"..\..\..\..\..\d\"), XFS.Path(@"c:\d\") };
             }
         }
 
@@ -172,11 +172,11 @@ public static IEnumerable<string[]> GetFullPath_RootedPathWithRelativeSegments_C
         {
             get
             {
-                yield return new [] { XFS.Path(@"c:\a\b\..\c"), XFS.Path(@"c:\a\c") };
-                yield return new [] { XFS.Path(@"c:\a\b\.\.\..\.\c"), XFS.Path(@"c:\a\c") };
-                yield return new [] { XFS.Path(@"c:\a\b\.\c"), XFS.Path(@"c:\a\b\c") };
-                yield return new [] { XFS.Path(@"c:\a\b\.\.\.\.\c"), XFS.Path(@"c:\a\b\c") };
-                yield return new [] { XFS.Path(@"c:\a\..\..\c"), XFS.Path(@"c:\c") };
+                yield return new[] { XFS.Path(@"c:\a\b\..\c"), XFS.Path(@"c:\a\c") };
+                yield return new[] { XFS.Path(@"c:\a\b\.\.\..\.\c"), XFS.Path(@"c:\a\c") };
+                yield return new[] { XFS.Path(@"c:\a\b\.\c"), XFS.Path(@"c:\a\b\c") };
+                yield return new[] { XFS.Path(@"c:\a\b\.\.\.\.\c"), XFS.Path(@"c:\a\b\c") };
+                yield return new[] { XFS.Path(@"c:\a\..\..\c"), XFS.Path(@"c:\c") };
             }
         }
 
@@ -198,14 +198,14 @@ public static IEnumerable<string[]> GetFullPath_AbsolutePaths_Cases
         {
             get
             {
-                yield return new [] { XFS.Path(@"c:\a"), XFS.Path(@"/b"), XFS.Path(@"c:\b") };
-                yield return new [] { XFS.Path(@"c:\a"), XFS.Path(@"/b\"), XFS.Path(@"c:\b\") };
-                yield return new [] { XFS.Path(@"c:\a"), XFS.Path(@"\b"), XFS.Path(@"c:\b") };
-                yield return new [] { XFS.Path(@"c:\a"), XFS.Path(@"\b\..\c"), XFS.Path(@"c:\c") };
-                yield return new [] { XFS.Path(@"z:\a"), XFS.Path(@"\b\..\c"), XFS.Path(@"z:\c") };
-                yield return new [] { XFS.Path(@"z:\a"), XFS.Path(@"\\computer\share\c"), XFS.Path(@"\\computer\share\c") };
-                yield return new [] { XFS.Path(@"z:\a"), XFS.Path(@"\\computer\share\c\..\d"), XFS.Path(@"\\computer\share\d") };
-                yield return new [] { XFS.Path(@"z:\a"), XFS.Path(@"\\computer\share\c\..\..\d"), XFS.Path(@"\\computer\share\d") };
+                yield return new[] { XFS.Path(@"c:\a"), XFS.Path(@"/b"), XFS.Path(@"c:\b") };
+                yield return new[] { XFS.Path(@"c:\a"), XFS.Path(@"/b\"), XFS.Path(@"c:\b\") };
+                yield return new[] { XFS.Path(@"c:\a"), XFS.Path(@"\b"), XFS.Path(@"c:\b") };
+                yield return new[] { XFS.Path(@"c:\a"), XFS.Path(@"\b\..\c"), XFS.Path(@"c:\c") };
+                yield return new[] { XFS.Path(@"z:\a"), XFS.Path(@"\b\..\c"), XFS.Path(@"z:\c") };
+                yield return new[] { XFS.Path(@"z:\a"), XFS.Path(@"\\computer\share\c"), XFS.Path(@"\\computer\share\c") };
+                yield return new[] { XFS.Path(@"z:\a"), XFS.Path(@"\\computer\share\c\..\d"), XFS.Path(@"\\computer\share\d") };
+                yield return new[] { XFS.Path(@"z:\a"), XFS.Path(@"\\computer\share\c\..\..\d"), XFS.Path(@"\\computer\share\d") };
             }
         }
 
@@ -274,7 +274,7 @@ public void GetFullPath_WithMultipleDirectorySeparators_ShouldReturnTheNormalize
             var mockPath = new MockPath(mockFileSystem);
 
             //Act
-            var actualFullPath =  mockPath.GetFullPath(XFS.Path(@"c:\foo\\//bar\file.dat"));
+            var actualFullPath = mockPath.GetFullPath(XFS.Path(@"c:\foo\\//bar\file.dat"));
 
             //Assert
             Assert.AreEqual(XFS.Path(@"c:\foo\bar\file.dat"), actualFullPath);
@@ -397,5 +397,61 @@ public void IsPathRooted_PathSentIn_DeterminesPathExists()
             //Assert
             Assert.AreEqual(true, result);
         }
+
+#if FEATURE_ADVANCED_PATH_OPERATIONS
+        [Test]
+        public void IsPathFullyQualified_WithAbsolutePath_ReturnsTrue()
+        {
+            //Arrange
+            var mockPath = new MockPath(new MockFileSystem());
+
+            //Act
+            var result = mockPath.IsPathFullyQualified(XFS.Path("C:\\directory\\file.txt"));
+
+            //Assert
+            Assert.IsTrue(result);
+        }
+
+        [Test]
+        public void IsPathFullyQualified_WithRelativePath_ReturnsFalse()
+        {
+            //Arrange
+            var mockPath = new MockPath(new MockFileSystem());
+
+            //Act
+            var result = mockPath.IsPathRooted(XFS.Path("directory\\file.txt"));
+
+            //Assert
+            Assert.IsFalse(result);
+        }
+        
+        [Test]
+        public void IsPathFullyQualified_WithRelativePathParts_ReturnsFalse()
+        {
+            //Arrange
+            var mockPath = new MockPath(new MockFileSystem());
+
+            //Act
+            var result = mockPath.IsPathRooted(XFS.Path("directory\\..\\file.txt"));
+
+            //Assert
+            Assert.IsFalse(result);
+        }
+
+        
+        
+        [Test]
+        public void GetRelativePath_Works()
+        {
+            //Arrange
+            var mockPath = new MockPath(new MockFileSystem());
+
+            //Act
+            var result = mockPath.GetRelativePath(XFS.Path("c:\\d"), XFS.Path("c:\\d\\e\\f.txt"));
+
+            //Assert
+            Assert.AreEqual(XFS.Path("e\\f.txt"), result);
+        }
+#endif
     }
 }
diff --git a/System.IO.Abstractions.TestingHelpers.Tests/System.IO.Abstractions.TestingHelpers.Tests.csproj b/System.IO.Abstractions.TestingHelpers.Tests/System.IO.Abstractions.TestingHelpers.Tests.csproj
index cdda5b513..aab6cfb50 100644
--- a/System.IO.Abstractions.TestingHelpers.Tests/System.IO.Abstractions.TestingHelpers.Tests.csproj
+++ b/System.IO.Abstractions.TestingHelpers.Tests/System.IO.Abstractions.TestingHelpers.Tests.csproj
@@ -7,7 +7,6 @@
     <RootNamespace>System.IO.Abstractions.TestingHelpers.Tests</RootNamespace>
     <IsPackable>false</IsPackable>
     <IsTestable>true</IsTestable>
-    <DefineConstants Condition="'$(TargetFramework)' == 'netcoreapp3.0'">$(DefineConstants);FEATURE_ASYNC_FILE;FEATURE_ENUMERATION_OPTIONS</DefineConstants>
   </PropertyGroup>
   <ItemGroup>
     <None Remove="TestFiles\SecondTestFile.txt" />
diff --git a/System.IO.Abstractions.TestingHelpers/System.IO.Abstractions.TestingHelpers.csproj b/System.IO.Abstractions.TestingHelpers/System.IO.Abstractions.TestingHelpers.csproj
index 6d3c39440..772bb052a 100644
--- a/System.IO.Abstractions.TestingHelpers/System.IO.Abstractions.TestingHelpers.csproj
+++ b/System.IO.Abstractions.TestingHelpers/System.IO.Abstractions.TestingHelpers.csproj
@@ -7,7 +7,6 @@
         <PackageProjectUrl>https://github.com/System-IO-Abstractions/System.IO.Abstractions</PackageProjectUrl>
         <PackageLicenseExpression>MIT</PackageLicenseExpression>
         <PackageTags>testing</PackageTags>
-        <DefineConstants Condition="'$(TargetFramework)' == 'netstandard2.1'">$(DefineConstants);FEATURE_ASYNC_FILE;FEATURE_ENUMERATION_OPTIONS</DefineConstants>
     </PropertyGroup>
     <ItemGroup>
         <ProjectReference Include="..\System.IO.Abstractions\System.IO.Abstractions.csproj" />
diff --git a/System.IO.Abstractions/IPath.cs b/System.IO.Abstractions/IPath.cs
index 2d6651d81..43270776c 100644
--- a/System.IO.Abstractions/IPath.cs
+++ b/System.IO.Abstractions/IPath.cs
@@ -51,5 +51,13 @@ public interface IPath
         bool HasExtension(string path);
         /// <inheritdoc cref="Path.IsPathRooted(string)"/>
         bool IsPathRooted(string path);
+
+#if FEATURE_ADVANCED_PATH_OPERATIONS
+        /// <inheritdoc cref="Path.IsPathFullyQualified(string)"/>
+        bool IsPathFullyQualified(string path);
+        
+        /// <inheritdoc cref="Path.GetRelativePath(string,string)"/>
+        string GetRelativePath(string relativeTo, string path);
+#endif
     }
 }
\ No newline at end of file
diff --git a/System.IO.Abstractions/PathBase.cs b/System.IO.Abstractions/PathBase.cs
index d87853bfc..142bce6ad 100644
--- a/System.IO.Abstractions/PathBase.cs
+++ b/System.IO.Abstractions/PathBase.cs
@@ -86,5 +86,13 @@ internal PathBase() { }
 
         /// <inheritdoc cref="Path.IsPathRooted(string)"/>
         public abstract bool IsPathRooted(string path);
+
+#if FEATURE_ADVANCED_PATH_OPERATIONS
+        /// <inheritdoc />
+        public abstract bool IsPathFullyQualified(string path);
+        
+        /// <inheritdoc />
+        public abstract string GetRelativePath(string relativeTo, string path);
+#endif
     }
 }
diff --git a/System.IO.Abstractions/PathWrapper.cs b/System.IO.Abstractions/PathWrapper.cs
index c4bac2fb1..aafca0b2c 100644
--- a/System.IO.Abstractions/PathWrapper.cs
+++ b/System.IO.Abstractions/PathWrapper.cs
@@ -118,6 +118,18 @@ public override bool HasExtension(string path)
             return Path.HasExtension(path);
         }
 
+#if FEATURE_ADVANCED_PATH_OPERATIONS
+        public override bool IsPathFullyQualified(string path)
+        {
+            return Path.IsPathFullyQualified(path);
+        }
+
+        public override string GetRelativePath(string relativeTo, string path)
+        {
+            return Path.GetRelativePath(relativeTo, path);
+        }
+#endif
+
         public override bool IsPathRooted(string path)
         {
             return Path.IsPathRooted(path);
diff --git a/System.IO.Abstractions/System.IO.Abstractions.csproj b/System.IO.Abstractions/System.IO.Abstractions.csproj
index 3faff2155..3ed380e75 100644
--- a/System.IO.Abstractions/System.IO.Abstractions.csproj
+++ b/System.IO.Abstractions/System.IO.Abstractions.csproj
@@ -7,7 +7,7 @@
     <PackageProjectUrl>https://github.com/System-IO-Abstractions/System.IO.Abstractions</PackageProjectUrl>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>
     <PackageTags>testing</PackageTags>
-    <DefineConstants Condition="'$(TargetFramework)' == 'netstandard2.1'">$(DefineConstants);FEATURE_ASYNC_FILE;FEATURE_ENUMERATION_OPTIONS</DefineConstants>
+    <DefineConstants Condition="'$(TargetFramework)' == 'netstandard2.1'">$(DefineConstants);FEATURE_ASYNC_FILE;FEATURE_ENUMERATION_OPTIONS;FEATURE_ADVANCED_PATH_OPERATIONS</DefineConstants>
   </PropertyGroup>
   <ItemGroup Condition="'$(TargetFramework)' != 'net461'">
     <PackageReference Include="System.IO.FileSystem.AccessControl" Version="4.7.0"/>
diff --git a/version.json b/version.json
index 70240ba98..7dd9adefb 100644
--- a/version.json
+++ b/version.json
@@ -1,6 +1,6 @@
 {
   "$schema": "https://raw.githubusercontent.com/AArnott/Nerdbank.GitVersioning/master/src/NerdBank.GitVersioning/version.schema.json",
-  "version": "8.1",
+  "version": "9.0",
   "assemblyVersion": {
     "precision": "major"
   },