diff --git a/build/RuntimeStore.targets b/build/RuntimeStore.targets
index c369b30a0a..89a0e289b1 100644
--- a/build/RuntimeStore.targets
+++ b/build/RuntimeStore.targets
@@ -207,6 +207,7 @@
     <!-- Trim packages guaranteed to be in the runtime but isn't included in our runtime store -->
     <ItemGroup>
       <PackagesToTrim Include="runtime.win-arm64.runtime.native.system.data.sqlclient.sni" />
+      <ExistingStoreManifests Include="$(_ExistingManifestsDirectory)*.xml" />
     </ItemGroup>
 
     <MSBuild Projects="$(_WorkRoot)RS.Manifest\RS.Manifest.csproj"
@@ -216,6 +217,12 @@
     </MSBuild>
 
     <RepoTasks.CreateCommonManifest DestinationFilePath="$(ArtifactsDir)$(CommonManifestFileName)" PackageDefinitions="@(_PackageDefinitions)" Packages="@(PackagesToTrim)"/>
+
+    <!-- Trim built manifest with existing manifests -->
+    <RepoTasks.ComposeNewStore
+      ExistingManifests="@(ExistingStoreManifests)"
+      NewManifests="$(ArtifactsDir)$(CommonManifestFileName)"
+      ManifestDestination="$(ArtifactsDir)$(CommonManifestFileName)"/>
   </Target>
 
   <Target Name="AddManifestsToMetapackage">
diff --git a/build/tasks/ComposeNewStore.cs b/build/tasks/ComposeNewStore.cs
index 90f601e0a2..2ad23089d2 100644
--- a/build/tasks/ComposeNewStore.cs
+++ b/build/tasks/ComposeNewStore.cs
@@ -17,19 +17,15 @@ namespace RepoTasks
         [Required]
         public ITaskItem[] NewManifests { get; set; }
 
-        [Required]
         public ITaskItem[] RuntimeStoreFiles { get; set; }
 
-        [Required]
         public ITaskItem[] RuntimeStoreSymbolFiles { get; set; }
 
         [Required]
         public string ManifestDestination { get; set; }
 
-        [Required]
         public string StoreDestination { get; set; }
 
-        [Required]
         public string SymbolsDestination { get; set; }
 
         public override bool Execute()
@@ -58,45 +54,51 @@ namespace RepoTasks
                 }
             }
 
-            // Insert new runtime store files
-            foreach (var storeFile in RuntimeStoreFiles)
+            if (RuntimeStoreFiles != null)
             {
-                // format: {bitness}}/{tfm}}/{id}/{version}}/...
-                var recursiveDir = storeFile.GetMetadata("RecursiveDir");
-                var components = recursiveDir.Split(Path.DirectorySeparatorChar);
-                var id = components[2];
-                var version = components[3];
-
-                if (!existingFiles.TryGetValue(id, out var versions) || !versions.Contains(version))
+                // Insert new runtime store files
+                foreach (var storeFile in RuntimeStoreFiles)
                 {
-                    var destinationDir = Path.Combine(StoreDestination, recursiveDir);
-                    if (!Directory.Exists(Path.Combine(StoreDestination, recursiveDir)))
-                    {
-                        Directory.CreateDirectory(destinationDir);
-                    }
+                    // format: {bitness}}/{tfm}}/{id}/{version}}/...
+                    var recursiveDir = storeFile.GetMetadata("RecursiveDir");
+                    var components = recursiveDir.Split(Path.DirectorySeparatorChar);
+                    var id = components[2];
+                    var version = components[3];
 
-                    File.Copy(storeFile.GetMetadata("FullPath"), Path.Combine(destinationDir, $"{storeFile.GetMetadata("Filename")}{storeFile.GetMetadata("Extension")}"), overwrite: true);
+                    if (!existingFiles.TryGetValue(id, out var versions) || !versions.Contains(version))
+                    {
+                        var destinationDir = Path.Combine(StoreDestination, recursiveDir);
+                        if (!Directory.Exists(Path.Combine(StoreDestination, recursiveDir)))
+                        {
+                            Directory.CreateDirectory(destinationDir);
+                        }
+
+                        File.Copy(storeFile.GetMetadata("FullPath"), Path.Combine(destinationDir, $"{storeFile.GetMetadata("Filename")}{storeFile.GetMetadata("Extension")}"), overwrite: true);
+                    }
                 }
             }
 
-            // Insert new runtime store files
-            foreach (var symbolFile in RuntimeStoreSymbolFiles)
+            if (RuntimeStoreSymbolFiles != null)
             {
-                // format: {bitness}}/{tfm}}/{id}/{version}}/...
-                var recursiveDir = symbolFile.GetMetadata("RecursiveDir");
-                var components = recursiveDir.Split(Path.DirectorySeparatorChar);
-                var id = components[2];
-                var version = components[3];
-
-                if (!existingFiles.TryGetValue(id, out var versions) || !versions.Contains(version))
+                // Insert new runtime store symbol files
+                foreach (var symbolFile in RuntimeStoreSymbolFiles)
                 {
-                    var destinationDir = Path.Combine(SymbolsDestination, recursiveDir);
-                    if (!Directory.Exists(Path.Combine(SymbolsDestination, recursiveDir)))
-                    {
-                        Directory.CreateDirectory(destinationDir);
-                    }
+                    // format: {bitness}}/{tfm}}/{id}/{version}}/...
+                    var recursiveDir = symbolFile.GetMetadata("RecursiveDir");
+                    var components = recursiveDir.Split(Path.DirectorySeparatorChar);
+                    var id = components[2];
+                    var version = components[3];
 
-                    File.Copy(symbolFile.GetMetadata("FullPath"), Path.Combine(destinationDir, $"{symbolFile.GetMetadata("Filename")}{symbolFile.GetMetadata("Extension")}"), overwrite: true);
+                    if (!existingFiles.TryGetValue(id, out var versions) || !versions.Contains(version))
+                    {
+                        var destinationDir = Path.Combine(SymbolsDestination, recursiveDir);
+                        if (!Directory.Exists(Path.Combine(SymbolsDestination, recursiveDir)))
+                        {
+                            Directory.CreateDirectory(destinationDir);
+                        }
+
+                        File.Copy(symbolFile.GetMetadata("FullPath"), Path.Combine(destinationDir, $"{symbolFile.GetMetadata("Filename")}{symbolFile.GetMetadata("Extension")}"), overwrite: true);
+                    }
                 }
             }