diff --git a/src/Orchard.Web/Modules/Orchard.Packaging/Services/PackageBuilder.cs b/src/Orchard.Web/Modules/Orchard.Packaging/Services/PackageBuilder.cs
index aa6555520..2cbbad486 100644
--- a/src/Orchard.Web/Modules/Orchard.Packaging/Services/PackageBuilder.cs
+++ b/src/Orchard.Web/Modules/Orchard.Packaging/Services/PackageBuilder.cs
@@ -6,6 +6,7 @@ using System.Net.Mime;
 using System.Reflection;
 using System.Xml.Linq;
 using NuGet;
+using Orchard.Environment;
 using Orchard.Environment.Extensions;
 using Orchard.Environment.Extensions.Models;
 using Orchard.FileSystems.VirtualPath;
@@ -18,6 +19,7 @@ namespace Orchard.Packaging.Services {
     public class PackageBuilder : IPackageBuilder {
         private readonly IWebSiteFolder _webSiteFolder;
         private readonly IVirtualPathProvider _virtualPathProvider;
+        private readonly IOrchardFrameworkAssemblies _frameworkAssemblies;
 
         private static readonly string[] _ignoredThemeExtensions = new[] {
             "obj", "pdb", "exclude"
@@ -34,9 +36,12 @@ namespace Orchard.Packaging.Services {
         }
 
         public PackageBuilder(IWebSiteFolder webSiteFolder,
-            IVirtualPathProvider virtualPathProvider) {
+            IVirtualPathProvider virtualPathProvider,
+            IOrchardFrameworkAssemblies frameworkAssemblies) {
+
             _webSiteFolder = webSiteFolder;
             _virtualPathProvider = virtualPathProvider;
+            _frameworkAssemblies = frameworkAssemblies;
         }
 
         public Stream BuildPackage(ExtensionDescriptor extensionDescriptor) {
@@ -112,10 +117,14 @@ namespace Orchard.Packaging.Services {
 
             foreach (var entry in entries) {
                 var assemblyName = new AssemblyName(entry.Include.Value);
-                string virtualPath = _virtualPathProvider.GetReferenceVirtualPath(context.SourcePath, assemblyName.Name, entry.HintPath != null ? entry.HintPath.Value : null);
 
-                if (!string.IsNullOrEmpty(virtualPath)) {
-                    EmbedVirtualFile(context, virtualPath, MediaTypeNames.Application.Octet);
+                // If it is not a core assembly
+                if (_frameworkAssemblies.GetFrameworkAssemblies().FirstOrDefault(assembly => assembly.FullName.Equals(assemblyName.FullName)) == null) {
+                    string virtualPath = _virtualPathProvider.GetReferenceVirtualPath(context.SourcePath, assemblyName.Name, entry.HintPath != null ? entry.HintPath.Value : null);
+
+                    if (!string.IsNullOrEmpty(virtualPath)) {
+                        EmbedVirtualFile(context, virtualPath, MediaTypeNames.Application.Octet);
+                    }
                 }
             }
         }
diff --git a/src/Orchard/Environment/IOrchardFrameworkAssemblies.cs b/src/Orchard/Environment/IOrchardFrameworkAssemblies.cs
new file mode 100644
index 000000000..2402cfb98
--- /dev/null
+++ b/src/Orchard/Environment/IOrchardFrameworkAssemblies.cs
@@ -0,0 +1,14 @@
+using System.Collections.Generic;
+using System.Reflection;
+
+namespace Orchard.Environment {
+    public interface IOrchardFrameworkAssemblies : IDependency {
+        IEnumerable<AssemblyName> GetFrameworkAssemblies();
+    }
+
+    public class DefaultOrchardFrameworkAssemblies : IOrchardFrameworkAssemblies {
+        public IEnumerable<AssemblyName> GetFrameworkAssemblies() {
+            return typeof (IDependency).Assembly.GetReferencedAssemblies();
+        }
+    }
+}
diff --git a/src/Orchard/Mvc/ViewEngines/Razor/IRazorCompilationEvents.cs b/src/Orchard/Mvc/ViewEngines/Razor/IRazorCompilationEvents.cs
index c0933ff0f..a0d2b3769 100644
--- a/src/Orchard/Mvc/ViewEngines/Razor/IRazorCompilationEvents.cs
+++ b/src/Orchard/Mvc/ViewEngines/Razor/IRazorCompilationEvents.cs
@@ -7,7 +7,6 @@ using System.Web.WebPages.Razor;
 using Orchard.Environment;
 using Orchard.Environment.Extensions.Loaders;
 using Orchard.FileSystems.Dependencies;
-using Orchard.FileSystems.VirtualPath;
 
 namespace Orchard.Mvc.ViewEngines.Razor {
     public interface IRazorCompilationEvents {
diff --git a/src/Orchard/Orchard.Framework.csproj b/src/Orchard/Orchard.Framework.csproj
index 3e620961c..dc713d2b6 100644
--- a/src/Orchard/Orchard.Framework.csproj
+++ b/src/Orchard/Orchard.Framework.csproj
@@ -185,6 +185,7 @@
     <Compile Include="Environment\Features\FeatureManager.cs" />
     <Compile Include="Environment\IAssemblyLoader.cs" />
     <Compile Include="Environment\HostComponentsConfigModule.cs" />
+    <Compile Include="Environment\IOrchardFrameworkAssemblies.cs" />
     <Compile Include="Environment\ViewsBackgroundCompilation.cs" />
     <Compile Include="Environment\Warmup\StartupResult.cs" />
     <Compile Include="Environment\Warmup\WarmupUtility.cs" />