diff --git a/TestAssets/TestProjects/PortableTests/PortableAppWithIntentionalManagedDowngrade/.noautoupdate b/TestAssets/TestProjects/PortableTests/PortableAppWithIntentionalManagedDowngrade/.noautoupdate
new file mode 100644
index 000000000..e69de29bb
diff --git a/scripts/update-dependencies/UpdateFilesTargets.cs b/scripts/update-dependencies/UpdateFilesTargets.cs
index c4a7eefc0..625fd329c 100644
--- a/scripts/update-dependencies/UpdateFilesTargets.cs
+++ b/scripts/update-dependencies/UpdateFilesTargets.cs
@@ -85,9 +85,12 @@ namespace Microsoft.DotNet.Scripts
         {
             List<DependencyInfo> dependencyInfos = c.GetDependencyInfos();
 
+            const string noUpdateFileName = ".noautoupdate";
+
             IEnumerable<string> projectJsonFiles = Enumerable.Union(
                 Directory.GetFiles(Dirs.RepoRoot, "project.json", SearchOption.AllDirectories),
-                Directory.GetFiles(Path.Combine(Dirs.RepoRoot, @"src\dotnet\commands\dotnet-new"), "project.json.pretemplate", SearchOption.AllDirectories));
+                Directory.GetFiles(Path.Combine(Dirs.RepoRoot, @"src\dotnet\commands\dotnet-new"), "project.json.pretemplate", SearchOption.AllDirectories))
+                .Where(p => !File.Exists(Path.Combine(Path.GetDirectoryName(p), noUpdateFileName)));
 
             JObject projectRoot;
             foreach (string projectJsonFile in projectJsonFiles)