diff --git a/src/Umbraco.ModelsBuilder.Embedded/PureLiveModelFactory.cs b/src/Umbraco.ModelsBuilder.Embedded/PureLiveModelFactory.cs
index e52e438b43..b5997b8419 100644
--- a/src/Umbraco.ModelsBuilder.Embedded/PureLiveModelFactory.cs
+++ b/src/Umbraco.ModelsBuilder.Embedded/PureLiveModelFactory.cs
@@ -452,7 +452,7 @@ namespace Umbraco.ModelsBuilder.Embedded
                 try
                 {
                     var assemblyPath = GetOutputAssemblyPath(currentHash);
-                    RoslynCompiler.CompileToFile(_hostingEnvironment.MapPathContentRoot(projFile), assemblyPath);
+                    RoslynCompiler.CompileToFile(projFile, assemblyPath);
                     assembly = ReloadAssembly(assemblyPath);
                     File.WriteAllText(dllPathFile, assembly.Location);
                     File.WriteAllText(modelsHashFile, currentHash);
@@ -494,7 +494,7 @@ namespace Umbraco.ModelsBuilder.Embedded
             try
             {
                 var assemblyPath = GetOutputAssemblyPath(currentHash);
-                RoslynCompiler.CompileToFile(_hostingEnvironment.MapPathContentRoot(projFile), assemblyPath);
+                RoslynCompiler.CompileToFile(projFile, assemblyPath);
                 assembly = ReloadAssembly(assemblyPath);
                 File.WriteAllText(dllPathFile, assemblyPath);
                 File.WriteAllText(modelsHashFile, currentHash);
diff --git a/src/Umbraco.Web.Common/AspNetCore/AspNetCoreHostingEnvironment.cs b/src/Umbraco.Web.Common/AspNetCore/AspNetCoreHostingEnvironment.cs
index 21301bc01a..a78565c977 100644
--- a/src/Umbraco.Web.Common/AspNetCore/AspNetCoreHostingEnvironment.cs
+++ b/src/Umbraco.Web.Common/AspNetCore/AspNetCoreHostingEnvironment.cs
@@ -79,16 +79,13 @@ namespace Umbraco.Web.Common.AspNetCore
             }
         }
 
-        public string MapPathWebRoot(string path)
-        {
-            var newPath = path.TrimStart('~', '/').Replace('/', Path.DirectorySeparatorChar).Replace('\\', Path.DirectorySeparatorChar);
-            return Path.Combine(_webHostEnvironment.WebRootPath, newPath);
-        }
+        public string MapPathWebRoot(string path) => MapPath(_webHostEnvironment.WebRootPath, path);
+        public string MapPathContentRoot(string path) => MapPath(_webHostEnvironment.ContentRootPath, path);
 
-        public string MapPathContentRoot(string path)
+        private string MapPath(string root, string path)
         {
-            var newPath = path.TrimStart('~', '/').Replace('/', Path.DirectorySeparatorChar).Replace('\\', Path.DirectorySeparatorChar);
-            return Path.Combine(_webHostEnvironment.ContentRootPath, newPath);
+            var newPath = path.Replace('/', Path.DirectorySeparatorChar).Replace('\\', Path.DirectorySeparatorChar);
+            return newPath.StartsWith(root) ? newPath : Path.Combine(root, newPath.TrimStart('~', '/'));
         }
 
         public string ToAbsolute(string virtualPath)
diff --git a/src/Umbraco.Web/AspNet/AspNetHostingEnvironment.cs b/src/Umbraco.Web/AspNet/AspNetHostingEnvironment.cs
index 8b9cfe7aa6..cc8fc975d2 100644
--- a/src/Umbraco.Web/AspNet/AspNetHostingEnvironment.cs
+++ b/src/Umbraco.Web/AspNet/AspNetHostingEnvironment.cs
@@ -49,7 +49,8 @@ namespace Umbraco.Web.Hosting
                 return HostingEnvironment.MapPath(path);
 
             // this will be the case in unit tests, we'll manually map the path
-            return Path.Combine(ApplicationPhysicalPath, path.TrimStart('~', '/'));
+            var newPath = path.Replace('/', Path.DirectorySeparatorChar).Replace('\\', Path.DirectorySeparatorChar);
+            return newPath.StartsWith(ApplicationPhysicalPath) ? newPath : Path.Combine(ApplicationPhysicalPath, newPath.TrimStart('~', '/'));
         }
 
         public string MapPathContentRoot(string path) => MapPathWebRoot(path);