diff --git a/src/Orchard.Tests.Modules/Migrations/SchemaCommandGeneratorTests.cs b/src/Orchard.Tests.Modules/Migrations/SchemaCommandGeneratorTests.cs
index 1307339b5..551fffe5b 100644
--- a/src/Orchard.Tests.Modules/Migrations/SchemaCommandGeneratorTests.cs
+++ b/src/Orchard.Tests.Modules/Migrations/SchemaCommandGeneratorTests.cs
@@ -125,7 +125,7 @@ Features:
             public IEnumerable<ExtensionDescriptor> AvailableExtensions() {
                 foreach (var e in Manifests) {
                     string name = e.Key;
-                    yield return ExtensionFolders.GetDescriptorForExtension("~/", name, DefaultExtensionTypes.Module, Manifests[name]);
+                    yield return ExtensionHarvester.GetDescriptorForExtension("~/", name, DefaultExtensionTypes.Module, Manifests[name]);
                 }
             }
         }
diff --git a/src/Orchard.Tests.Modules/Recipes/Services/RecipeManagerTests.cs b/src/Orchard.Tests.Modules/Recipes/Services/RecipeManagerTests.cs
index 540d8f922..372cba562 100644
--- a/src/Orchard.Tests.Modules/Recipes/Services/RecipeManagerTests.cs
+++ b/src/Orchard.Tests.Modules/Recipes/Services/RecipeManagerTests.cs
@@ -62,7 +62,8 @@ namespace Orchard.Tests.Modules.Recipes.Services {
             }
 
             var builder = new ContainerBuilder();
-            _folders = new ModuleFolders(new[] { _tempFolderName }, new StubCacheManager(), new StubWebSiteFolder());
+            var harvester = new ExtensionHarvester(new StubCacheManager(), new StubWebSiteFolder());
+            _folders = new ModuleFolders(new[] { _tempFolderName }, harvester);
             builder.RegisterType<RecipeManager>().As<IRecipeManager>();
             builder.RegisterType<RecipeHarvester>().As<IRecipeHarvester>();
             builder.RegisterType<RecipeStepExecutor>().As<IRecipeStepExecutor>();
diff --git a/src/Orchard.Tests/DataMigration/DataMigrationTests.cs b/src/Orchard.Tests/DataMigration/DataMigrationTests.cs
index ae4b65864..9697aa0aa 100644
--- a/src/Orchard.Tests/DataMigration/DataMigrationTests.cs
+++ b/src/Orchard.Tests/DataMigration/DataMigrationTests.cs
@@ -92,7 +92,7 @@ namespace Orchard.Tests.DataMigration {
             public IEnumerable<ExtensionDescriptor> AvailableExtensions() {
                 foreach (var e in Manifests) {
                     string name = e.Key;
-                    yield return ExtensionFolders.GetDescriptorForExtension("~/", name, DefaultExtensionTypes.Module, Manifests[name]);
+                    yield return ExtensionHarvester.GetDescriptorForExtension("~/", name, DefaultExtensionTypes.Module, Manifests[name]);
                 }
             }
         }
diff --git a/src/Orchard.Tests/Environment/Extensions/ExtensionFoldersTests.cs b/src/Orchard.Tests/Environment/Extensions/ExtensionFoldersTests.cs
index 9fddee3d5..bf677980d 100644
--- a/src/Orchard.Tests/Environment/Extensions/ExtensionFoldersTests.cs
+++ b/src/Orchard.Tests/Environment/Extensions/ExtensionFoldersTests.cs
@@ -49,7 +49,8 @@ namespace Orchard.Tests.Environment.Extensions {
 
         [Test]
         public void IdsFromFoldersWithModuleTxtShouldBeListed() {
-            IExtensionFolders folders = new ModuleFolders(new[] { _tempFolderName }, new StubCacheManager(), new StubWebSiteFolder());
+            var harvester = new ExtensionHarvester(new StubCacheManager(), new StubWebSiteFolder());
+            IExtensionFolders folders = new ModuleFolders(new[] { _tempFolderName }, harvester);
             var ids = folders.AvailableExtensions().Select(d => d.Id);
             Assert.That(ids.Count(), Is.EqualTo(5));
             Assert.That(ids, Has.Some.EqualTo("Sample1")); // Sample1 - obviously
@@ -61,7 +62,8 @@ namespace Orchard.Tests.Environment.Extensions {
 
         [Test]
         public void ModuleTxtShouldBeParsedAndReturnedAsYamlDocument() {
-            IExtensionFolders folders = new ModuleFolders(new[] { _tempFolderName }, new StubCacheManager(), new StubWebSiteFolder());
+            var harvester = new ExtensionHarvester(new StubCacheManager(), new StubWebSiteFolder());
+            IExtensionFolders folders = new ModuleFolders(new[] { _tempFolderName }, harvester);
             var sample1 = folders.AvailableExtensions().Single(d => d.Id == "Sample1");
             Assert.That(sample1.Id, Is.Not.Empty);
             Assert.That(sample1.Author, Is.EqualTo("Bertrand Le Roy")); // Sample1
@@ -69,7 +71,8 @@ namespace Orchard.Tests.Environment.Extensions {
 
         [Test]
         public void NamesFromFoldersWithModuleTxtShouldFallBackToIdIfNotGiven() {
-            IExtensionFolders folders = new ModuleFolders(new[] { _tempFolderName }, new StubCacheManager(), new StubWebSiteFolder());
+            var harvester = new ExtensionHarvester(new StubCacheManager(), new StubWebSiteFolder());
+            IExtensionFolders folders = new ModuleFolders(new[] { _tempFolderName }, harvester);
             var names = folders.AvailableExtensions().Select(d => d.Name);
             Assert.That(names.Count(), Is.EqualTo(5));
             Assert.That(names, Has.Some.EqualTo("Le plug-in français")); // Sample1
@@ -81,7 +84,8 @@ namespace Orchard.Tests.Environment.Extensions {
 
         [Test]
         public void PathsFromFoldersWithModuleTxtShouldFallBackAppropriatelyIfNotGiven() {
-            IExtensionFolders folders = new ModuleFolders(new[] { _tempFolderName }, new StubCacheManager(), new StubWebSiteFolder());
+            var harvester = new ExtensionHarvester(new StubCacheManager(), new StubWebSiteFolder());
+            IExtensionFolders folders = new ModuleFolders(new[] { _tempFolderName }, harvester);
             var paths = folders.AvailableExtensions().Select(d => d.Path);
             Assert.That(paths.Count(), Is.EqualTo(5));
             Assert.That(paths, Has.Some.EqualTo("Sample1")); // Sample1 - Id, Name invalid URL segment
diff --git a/src/Orchard.Tests/Environment/Extensions/ExtensionLoaderCoordinatorTests.cs b/src/Orchard.Tests/Environment/Extensions/ExtensionLoaderCoordinatorTests.cs
index a88a7576e..c9b62564a 100644
--- a/src/Orchard.Tests/Environment/Extensions/ExtensionLoaderCoordinatorTests.cs
+++ b/src/Orchard.Tests/Environment/Extensions/ExtensionLoaderCoordinatorTests.cs
@@ -46,7 +46,7 @@ namespace Orchard.Tests.Environment.Extensions {
             public IEnumerable<ExtensionDescriptor> AvailableExtensions() {
                 foreach (var e in Manifests) {
                     string name = e.Key;
-                    yield return ExtensionFolders.GetDescriptorForExtension("~/", name, _extensionType, Manifests[name]);
+                    yield return ExtensionHarvester.GetDescriptorForExtension("~/", name, _extensionType, Manifests[name]);
                 }
             }
         }
diff --git a/src/Orchard.Tests/Environment/Extensions/ExtensionManagerTests.cs b/src/Orchard.Tests/Environment/Extensions/ExtensionManagerTests.cs
index 4f7b6245b..0b62c0c47 100644
--- a/src/Orchard.Tests/Environment/Extensions/ExtensionManagerTests.cs
+++ b/src/Orchard.Tests/Environment/Extensions/ExtensionManagerTests.cs
@@ -51,7 +51,7 @@ namespace Orchard.Tests.Environment.Extensions {
             public IEnumerable<ExtensionDescriptor> AvailableExtensions() {
                 foreach (var e in Manifests) {
                     string name = e.Key;
-                    yield return ExtensionFolders.GetDescriptorForExtension("~/", name, _extensionType, Manifests[name]);
+                    yield return ExtensionHarvester.GetDescriptorForExtension("~/", name, _extensionType, Manifests[name]);
                 }
             }
         }
diff --git a/src/Orchard.Web/Modules/Orchard.Packaging/Services/PackageManager.cs b/src/Orchard.Web/Modules/Orchard.Packaging/Services/PackageManager.cs
index ea8ac6aac..77b4660d9 100644
--- a/src/Orchard.Web/Modules/Orchard.Packaging/Services/PackageManager.cs
+++ b/src/Orchard.Web/Modules/Orchard.Packaging/Services/PackageManager.cs
@@ -78,7 +78,7 @@ namespace Orchard.Packaging.Services {
             if (packageFile != null) {
                 string extensionId = Path.GetFileName(Path.GetDirectoryName(packageFile.Path).TrimEnd('/', '\\'));
                 using (StreamReader streamReader = new StreamReader(packageFile.GetStream())) {
-                    return ExtensionFolders.GetDescriptorForExtension("", extensionId, extensionType, streamReader.ReadToEnd());
+                    return ExtensionHarvester.GetDescriptorForExtension("", extensionId, extensionType, streamReader.ReadToEnd());
                 }
             }
 
diff --git a/src/Orchard/Environment/Extensions/Folders/ExtensionFolders.cs b/src/Orchard/Environment/Extensions/Folders/ExtensionHarvester.cs
similarity index 89%
rename from src/Orchard/Environment/Extensions/Folders/ExtensionFolders.cs
rename to src/Orchard/Environment/Extensions/Folders/ExtensionHarvester.cs
index 466494348..fbd25ee4e 100644
--- a/src/Orchard/Environment/Extensions/Folders/ExtensionFolders.cs
+++ b/src/Orchard/Environment/Extensions/Folders/ExtensionHarvester.cs
@@ -10,7 +10,7 @@ using Orchard.Logging;
 using Orchard.Utility.Extensions;
 
 namespace Orchard.Environment.Extensions.Folders {
-    public class ExtensionFolders : IExtensionFolders {
+    public class ExtensionHarvester : IExtensionHarvester {
         private const string NameSection = "name";
         private const string PathSection = "path";
         private const string DescriptionSection = "description";
@@ -29,23 +29,10 @@ namespace Orchard.Environment.Extensions.Folders {
         private const string PrioritySection = "priority";
         private const string FeaturesSection = "features";
 
-        private readonly IEnumerable<string> _paths;
-        private readonly string _manifestName;
-        private readonly string _extensionType;
-        private readonly bool _manifestIsOptional;
         private readonly ICacheManager _cacheManager;
         private readonly IWebSiteFolder _webSiteFolder;
 
-        protected ExtensionFolders(
-            IEnumerable<string> paths,
-            string manifestName,
-            bool manifestIsOptional,
-            ICacheManager cacheManager,
-            IWebSiteFolder webSiteFolder) {
-            _paths = paths;
-            _manifestName = manifestName;
-            _extensionType = manifestName == "Theme.txt" ? DefaultExtensionTypes.Theme : DefaultExtensionTypes.Module;
-            _manifestIsOptional = manifestIsOptional;
+        public ExtensionHarvester(ICacheManager cacheManager, IWebSiteFolder webSiteFolder) {
             _cacheManager = cacheManager;
             _webSiteFolder = webSiteFolder;
             Logger = NullLogger.Instance;
@@ -55,24 +42,30 @@ namespace Orchard.Environment.Extensions.Folders {
         public Localizer T { get; set; }
         public ILogger Logger { get; set; }
 
-        public IEnumerable<ExtensionDescriptor> AvailableExtensions() {
-            return _paths
-                .SelectMany(path => _cacheManager.Get(path, ctx => {
-                    ctx.Monitor(_webSiteFolder.WhenPathChanges(ctx.Key));
-                    return AvailableExtensionsInFolder(ctx.Key);
-                    }))
+        public IEnumerable<ExtensionDescriptor> HarvestExtensions(IEnumerable<string> paths, string extensionType, string manifestName, bool manifestIsOptional) {
+            return paths
+                .SelectMany(path => HarvestExtensions(path, extensionType, manifestName, manifestIsOptional))
                 .ToList();
         }
 
-        private List<ExtensionDescriptor> AvailableExtensionsInFolder(string path) {
+        private IEnumerable<ExtensionDescriptor> HarvestExtensions(string path, string extensionType, string manifestName, bool manifestIsOptional) {
+            string key = string.Format("{0}-{1}-{2}", path, manifestName, extensionType);
+
+            return _cacheManager.Get(key, ctx => {
+                ctx.Monitor(_webSiteFolder.WhenPathChanges(path));
+                return AvailableExtensionsInFolder(path, extensionType, manifestName, manifestIsOptional);
+            });
+        }
+
+        private List<ExtensionDescriptor> AvailableExtensionsInFolder(string path, string extensionType, string manifestName, bool manifestIsOptional) {
             Logger.Information("Start looking for extensions in '{0}'...", path);
             var subfolderPaths = _webSiteFolder.ListDirectories(path);
             var localList = new List<ExtensionDescriptor>();
             foreach (var subfolderPath in subfolderPaths) {
                 var extensionId = Path.GetFileName(subfolderPath.TrimEnd('/', '\\'));
-                var manifestPath = Path.Combine(subfolderPath, _manifestName);
+                var manifestPath = Path.Combine(subfolderPath, manifestName);
                 try {
-                    var descriptor = GetExtensionDescriptor(path, extensionId, manifestPath);
+                    var descriptor = GetExtensionDescriptor(path, extensionId, extensionType, manifestPath, manifestIsOptional);
 
                     if (descriptor == null)
                         continue;
@@ -124,12 +117,12 @@ namespace Orchard.Environment.Extensions.Folders {
             return extensionDescriptor;
         }
 
-        private ExtensionDescriptor GetExtensionDescriptor(string locationPath, string extensionId, string manifestPath) {
+        private ExtensionDescriptor GetExtensionDescriptor(string locationPath, string extensionId, string extensionType, string manifestPath, bool manifestIsOptional) {
             return _cacheManager.Get(manifestPath, context => {
                 context.Monitor(_webSiteFolder.WhenPathChanges(manifestPath));
                 var manifestText = _webSiteFolder.ReadFile(manifestPath);
                 if (manifestText == null) {
-                    if (_manifestIsOptional) {
+                    if (manifestIsOptional) {
                         manifestText = string.Format("Id: {0}", extensionId);
                     }
                     else {
@@ -137,14 +130,10 @@ namespace Orchard.Environment.Extensions.Folders {
                     }
                 }
 
-                return GetDescriptorForExtension(locationPath, extensionId, manifestText);
+                return GetDescriptorForExtension(locationPath, extensionId, extensionType, manifestText);
             });
         }
 
-        private ExtensionDescriptor GetDescriptorForExtension(string locationPath, string extensionId, string manifestText) {
-            return GetDescriptorForExtension(locationPath, extensionId, _extensionType, manifestText);
-        }
-
         private static Dictionary<string, string> ParseManifest(string manifestText) {
             var manifest = new Dictionary<string, string>();
 
diff --git a/src/Orchard/Environment/Extensions/Folders/IExtensionHarvester.cs b/src/Orchard/Environment/Extensions/Folders/IExtensionHarvester.cs
new file mode 100644
index 000000000..5afa502af
--- /dev/null
+++ b/src/Orchard/Environment/Extensions/Folders/IExtensionHarvester.cs
@@ -0,0 +1,8 @@
+using System.Collections.Generic;
+using Orchard.Environment.Extensions.Models;
+
+namespace Orchard.Environment.Extensions.Folders {
+    public interface IExtensionHarvester {
+        IEnumerable<ExtensionDescriptor> HarvestExtensions(IEnumerable<string> paths, string extensionType, string manifestName, bool manifestIsOptional);
+    }
+}
\ No newline at end of file
diff --git a/src/Orchard/Environment/Extensions/Folders/ModuleFolders.cs b/src/Orchard/Environment/Extensions/Folders/ModuleFolders.cs
index dd8569f41..b504661df 100644
--- a/src/Orchard/Environment/Extensions/Folders/ModuleFolders.cs
+++ b/src/Orchard/Environment/Extensions/Folders/ModuleFolders.cs
@@ -1,11 +1,18 @@
 using System.Collections.Generic;
-using Orchard.Caching;
-using Orchard.FileSystems.WebSite;
+using Orchard.Environment.Extensions.Models;
 
 namespace Orchard.Environment.Extensions.Folders {
-    public class ModuleFolders : ExtensionFolders {
-        public ModuleFolders(IEnumerable<string> paths, ICacheManager cacheManager, IWebSiteFolder webSiteFolder) : 
-            base(paths, "Module.txt", false/*isManifestOptional*/, cacheManager, webSiteFolder) {
+    public class ModuleFolders : IExtensionFolders {
+        private readonly IEnumerable<string> _paths;
+        private readonly IExtensionHarvester _extensionHarvester;
+
+        public ModuleFolders(IEnumerable<string> paths, IExtensionHarvester extensionHarvester)  {
+            _paths = paths;
+            _extensionHarvester = extensionHarvester;
+        }
+
+        public IEnumerable<ExtensionDescriptor> AvailableExtensions() {
+            return _extensionHarvester.HarvestExtensions(_paths, DefaultExtensionTypes.Module, "Module.txt", false/*isManifestOptional*/);
         }
     }
 }
\ No newline at end of file
diff --git a/src/Orchard/Environment/Extensions/Folders/ThemeFolders.cs b/src/Orchard/Environment/Extensions/Folders/ThemeFolders.cs
index b832514ad..c8a607e56 100644
--- a/src/Orchard/Environment/Extensions/Folders/ThemeFolders.cs
+++ b/src/Orchard/Environment/Extensions/Folders/ThemeFolders.cs
@@ -1,11 +1,18 @@
 using System.Collections.Generic;
-using Orchard.Caching;
-using Orchard.FileSystems.WebSite;
+using Orchard.Environment.Extensions.Models;
 
 namespace Orchard.Environment.Extensions.Folders {
-    public class ThemeFolders : ExtensionFolders {
-        public ThemeFolders(IEnumerable<string> paths, ICacheManager cacheManager, IWebSiteFolder webSiteFolder) : 
-            base(paths, "Theme.txt", false/*manifestIsOptional*/, cacheManager, webSiteFolder) {
+    public class ThemeFolders : IExtensionFolders {
+        private readonly IEnumerable<string> _paths;
+        private readonly IExtensionHarvester _extensionHarvester;
+
+        public ThemeFolders(IEnumerable<string> paths, IExtensionHarvester extensionHarvester) {
+            _paths = paths;
+            _extensionHarvester = extensionHarvester;
+        }
+
+        public IEnumerable<ExtensionDescriptor> AvailableExtensions() {
+            return _extensionHarvester.HarvestExtensions(_paths, DefaultExtensionTypes.Theme, "Theme.txt", false/*isManifestOptional*/);
         }
     }
 }
\ No newline at end of file
diff --git a/src/Orchard/Environment/OrchardStarter.cs b/src/Orchard/Environment/OrchardStarter.cs
index 7480ec7f3..4e7533c3d 100644
--- a/src/Orchard/Environment/OrchardStarter.cs
+++ b/src/Orchard/Environment/OrchardStarter.cs
@@ -81,6 +81,7 @@ namespace Orchard.Environment {
                         builder.RegisterType<ExtensionMonitoringCoordinator>().As<IExtensionMonitoringCoordinator>().SingleInstance();
                         builder.RegisterType<ExtensionManager>().As<IExtensionManager>().SingleInstance();
                         {
+                            builder.RegisterType<ExtensionHarvester>().As<IExtensionHarvester>().SingleInstance();
                             builder.RegisterType<ModuleFolders>().As<IExtensionFolders>().SingleInstance()
                                 .WithParameter(new NamedParameter("paths", new[] { "~/Core", "~/Modules" }));
                             builder.RegisterType<ThemeFolders>().As<IExtensionFolders>().SingleInstance()
diff --git a/src/Orchard/Orchard.Framework.csproj b/src/Orchard/Orchard.Framework.csproj
index 0adf5fcb3..bedebd48f 100644
--- a/src/Orchard/Orchard.Framework.csproj
+++ b/src/Orchard/Orchard.Framework.csproj
@@ -178,6 +178,7 @@
     <Compile Include="Caching\DefaultAsyncTokenProvider.cs" />
     <Compile Include="Environment\Extensions\ExtensionMonitoringCoordinator.cs" />
     <Compile Include="Caching\IAsyncTokenProvider.cs" />
+    <Compile Include="Environment\Extensions\Folders\IExtensionHarvester.cs" />
     <Compile Include="Environment\Extensions\IExtensionMonitoringCoordinator.cs" />
     <Compile Include="Environment\Extensions\OrchardSuppressDependencyAttribute.cs" />
     <Compile Include="Environment\Features\IFeatureManager.cs" />
@@ -710,7 +711,7 @@
     <Compile Include="Events\EventsRegistrationSource.cs" />
     <Compile Include="Environment\Configuration\IShellSettingsManagerEventHandler.cs" />
     <Compile Include="Events\IEventBus.cs" />
-    <Compile Include="Environment\Extensions\Folders\ExtensionFolders.cs" />
+    <Compile Include="Environment\Extensions\Folders\ExtensionHarvester.cs" />
     <Compile Include="Environment\Extensions\Models\Feature.cs" />
     <Compile Include="Environment\Extensions\Models\FeatureDescriptor.cs" />
     <Compile Include="Environment\Extensions\OrchardFeatureAttribute.cs" />