diff --git a/src/Http/Http.Abstractions/src/Extensions/MapMiddleware.cs b/src/Http/Http.Abstractions/src/Extensions/MapMiddleware.cs
index 35b25f40e62b..3122b7640909 100644
--- a/src/Http/Http.Abstractions/src/Extensions/MapMiddleware.cs
+++ b/src/Http/Http.Abstractions/src/Extensions/MapMiddleware.cs
@@ -64,7 +64,7 @@ public Task Invoke(HttpContext context)
             return _next(context);
         }
 
-        private async Task InvokeCore(HttpContext context, string matchedPath, string remainingPath)
+        private async Task InvokeCore(HttpContext context, PathString matchedPath, PathString remainingPath)
         {
             var path = context.Request.Path;
             var pathBase = context.Request.PathBase;
diff --git a/src/Http/Http.Abstractions/src/Extensions/UsePathBaseExtensions.cs b/src/Http/Http.Abstractions/src/Extensions/UsePathBaseExtensions.cs
index 0bdf4fcfed97..46280bb4f221 100644
--- a/src/Http/Http.Abstractions/src/Extensions/UsePathBaseExtensions.cs
+++ b/src/Http/Http.Abstractions/src/Extensions/UsePathBaseExtensions.cs
@@ -1,4 +1,4 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
@@ -26,7 +26,7 @@ public static IApplicationBuilder UsePathBase(this IApplicationBuilder app, Path
             }
 
             // Strip trailing slashes
-            pathBase = pathBase.Value?.TrimEnd('/');
+            pathBase = new PathString(pathBase.Value?.TrimEnd('/'));
             if (!pathBase.HasValue)
             {
                 return app;
@@ -35,4 +35,4 @@ public static IApplicationBuilder UsePathBase(this IApplicationBuilder app, Path
             return app.UseMiddleware<UsePathBaseMiddleware>(pathBase);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/Http/Http.Abstractions/src/Extensions/UsePathBaseMiddleware.cs b/src/Http/Http.Abstractions/src/Extensions/UsePathBaseMiddleware.cs
index 34ffc5738d40..ef7b9d586cfd 100644
--- a/src/Http/Http.Abstractions/src/Extensions/UsePathBaseMiddleware.cs
+++ b/src/Http/Http.Abstractions/src/Extensions/UsePathBaseMiddleware.cs
@@ -55,7 +55,7 @@ public Task Invoke(HttpContext context)
             return _next(context);
         }
 
-        private async Task InvokeCore(HttpContext context, string matchedPath, string remainingPath)
+        private async Task InvokeCore(HttpContext context, PathString matchedPath, PathString remainingPath)
         {
             var originalPath = context.Request.Path;
             var originalPathBase = context.Request.PathBase;
diff --git a/src/Http/Http.Abstractions/test/MapPathMiddlewareTests.cs b/src/Http/Http.Abstractions/test/MapPathMiddlewareTests.cs
index 48c718a47c16..acaa0e0bce6d 100644
--- a/src/Http/Http.Abstractions/test/MapPathMiddlewareTests.cs
+++ b/src/Http/Http.Abstractions/test/MapPathMiddlewareTests.cs
@@ -43,24 +43,27 @@ public void NullArguments_ArgumentNullException()
         }
 
         [Theory]
-        [InlineData("/foo", "", "/foo")]
-        [InlineData("/foo", "", "/foo/")]
-        [InlineData("/foo", "/Bar", "/foo")]
-        [InlineData("/foo", "/Bar", "/foo/cho")]
-        [InlineData("/foo", "/Bar", "/foo/cho/")]
-        [InlineData("/foo/cho", "/Bar", "/foo/cho")]
-        [InlineData("/foo/cho", "/Bar", "/foo/cho/do")]
-        public async Task PathMatchFunc_BranchTaken(string matchPath, string basePath, string requestPath)
+        [InlineData("/foo", "", "/foo", "/foo", "")]
+        [InlineData("/foo", "", "/foo/", "/foo", "/")]
+        [InlineData("/foo", "/Bar", "/foo", "/Bar/foo", "")]
+        [InlineData("/foo", "/Bar", "/foo/cho", "/Bar/foo", "/cho")]
+        [InlineData("/foo", "/Bar", "/foo/cho/", "/Bar/foo", "/cho/")]
+        [InlineData("/foo/cho", "/Bar", "/foo/cho", "/Bar/foo/cho", "")]
+        [InlineData("/foo/cho", "/Bar", "/foo/cho/do", "/Bar/foo/cho", "/do")]
+        [InlineData("/foo%42/cho", "/Bar%42", "/foo%42/cho/do%42", "/Bar%42/foo%42/cho", "/do%42")]
+        public async Task PathMatchFunc_BranchTaken(string matchPath, string basePath, string requestPath, string expectedPathBase, string expectedPath)
         {
             HttpContext context = CreateRequest(basePath, requestPath);
             var builder = new ApplicationBuilder(serviceProvider: null!);
-            builder.Map(matchPath, UseSuccess);
+            builder.Map(new PathString(matchPath), UseSuccess);
             var app = builder.Build();
             await app.Invoke(context);
 
             Assert.Equal(200, context.Response.StatusCode);
             Assert.Equal(basePath, context.Request.PathBase.Value);
             Assert.Equal(requestPath, context.Request.Path.Value);
+            Assert.Equal(expectedPathBase, (string)context.Items["test.PathBase"]!);
+            Assert.Equal(expectedPath, context.Items["test.Path"]);
         }
 
         [Theory]
diff --git a/src/Http/Http.Abstractions/test/UsePathBaseExtensionsTests.cs b/src/Http/Http.Abstractions/test/UsePathBaseExtensionsTests.cs
index a5511ef0c18b..ebb695ed0656 100644
--- a/src/Http/Http.Abstractions/test/UsePathBaseExtensionsTests.cs
+++ b/src/Http/Http.Abstractions/test/UsePathBaseExtensionsTests.cs
@@ -131,11 +131,23 @@ public Task PathBaseCanHaveUnicodeCharacters(string registeredPathBase, string p
             return TestPathBase(registeredPathBase, pathBase, requestPath, expectedPathBase, expectedPath);
         }
 
+        [Theory]
+        [InlineData("/b%42", "", "/b%42/something%42", "/b%42", "/something%42")]
+        [InlineData("/b%42", "", "/B%42/something%42", "/B%42", "/something%42")]
+        [InlineData("/b%42", "", "/b%42/Something%42", "/b%42", "/Something%42")]
+        [InlineData("/b%42", "/oldb%42", "/b%42/something%42", "/oldb%42/b%42", "/something%42")]
+        [InlineData("/b%42", "/oldb%42", "/b%42/Something%42", "/oldb%42/b%42", "/Something%42")]
+        [InlineData("/b%42", "/oldb%42", "/B%42/something%42", "/oldb%42/B%42", "/something%42")]
+        public Task PathBaseCanHavePercentCharacters(string registeredPathBase, string pathBase, string requestPath, string expectedPathBase, string expectedPath)
+        {
+            return TestPathBase(registeredPathBase, pathBase, requestPath, expectedPathBase, expectedPath);
+        }
+
         private static async Task TestPathBase(string registeredPathBase, string pathBase, string requestPath, string expectedPathBase, string expectedPath)
         {
             HttpContext requestContext = CreateRequest(pathBase, requestPath);
             var builder = CreateBuilder()
-                .UsePathBase(registeredPathBase);
+                .UsePathBase(new PathString(registeredPathBase));
             builder.Run(context =>
             {
                 context.Items["test.Path"] = context.Request.Path;