diff --git a/src/Orchard.Tests/Environment/DefaultCompositionStrategyTests.cs b/src/Orchard.Tests/Environment/DefaultCompositionStrategyTests.cs
index 468aa3932..822de39e9 100644
--- a/src/Orchard.Tests/Environment/DefaultCompositionStrategyTests.cs
+++ b/src/Orchard.Tests/Environment/DefaultCompositionStrategyTests.cs
@@ -7,9 +7,7 @@ using Autofac;
 using Autofac.Core;
 using Moq;
 using NUnit.Framework;
-using Orchard.ContentManagement;
 using Orchard.ContentManagement.Records;
-using Orchard.Environment;
 using Orchard.Environment.Configuration;
 using Orchard.Environment.Extensions;
 using Orchard.Environment.Extensions.Models;
@@ -27,7 +25,6 @@ namespace Orchard.Tests.Environment {
         private IEnumerable<ExtensionDescriptor> _extensionDescriptors;
         private IDictionary<string, IEnumerable<Type>> _featureTypes;
 
-
         [SetUp]
         public void Init() {
             var builder = new ContainerBuilder();
diff --git a/src/Orchard.Tests/Environment/Loaders/DynamicExtensionLoaderTests.cs b/src/Orchard.Tests/Environment/Loaders/DynamicExtensionLoaderTests.cs
new file mode 100644
index 000000000..96db8bf53
--- /dev/null
+++ b/src/Orchard.Tests/Environment/Loaders/DynamicExtensionLoaderTests.cs
@@ -0,0 +1,206 @@
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using Autofac;
+using Moq;
+using NUnit.Framework;
+using Orchard.Caching;
+using Orchard.Environment;
+using Orchard.Environment.Extensions.Compilers;
+using Orchard.Environment.Extensions.Loaders;
+using Orchard.FileSystems.AppData;
+using Orchard.FileSystems.Dependencies;
+using Orchard.FileSystems.VirtualPath;
+using Orchard.Services;
+using Orchard.Tests.Stubs;
+
+namespace Orchard.Tests.Environment.Loaders {
+    [TestFixture]
+    public class DynamicExtensionLoaderTests {
+        private IContainer _container;
+        private Mock<IProjectFileParser> _mockedStubProjectFileParser;
+        private Mock<IDependenciesFolder> _mockedDependenciesFolder;
+
+        [SetUp]
+        public void Init() {
+            var builder = new ContainerBuilder();
+            builder.RegisterType<DynamicExtensionLoaderAccessor>().As<DynamicExtensionLoaderAccessor>();
+
+            builder.RegisterType<DefaultBuildManager>().As<IBuildManager>();
+            builder.RegisterType<DefaultAssemblyProbingFolder>().As<IAssemblyProbingFolder>();
+            builder.RegisterType<StubHostEnvironment>().As<IHostEnvironment>();
+            builder.RegisterType<StubVirtualPathMonitor>().As<IVirtualPathMonitor>();
+            builder.RegisterType<StubVirtualPathProvider>().As<IVirtualPathProvider>();
+            builder.RegisterType<DefaultAssemblyLoader>().As<IAssemblyLoader>();
+            builder.RegisterType<StubClock>().As<IClock>();
+            builder.RegisterType<StubAppDataFolder>().As<IAppDataFolder>();
+            builder.RegisterType<StubCacheManager>().As<ICacheManager>();
+
+            _mockedStubProjectFileParser = new Mock<IProjectFileParser>();
+            builder.RegisterInstance(_mockedStubProjectFileParser.Object).As<IProjectFileParser>();
+            builder.RegisterInstance(new StubFileSystem(new StubClock())).As<StubFileSystem>();
+
+            _mockedDependenciesFolder = new Mock<IDependenciesFolder>();
+            builder.RegisterInstance(_mockedDependenciesFolder.Object).As<IDependenciesFolder>();
+
+            _container = builder.Build();
+        }
+
+        [Test]
+        public void GetDependenciesContainsNoDuplicatesTest() {
+            const string fileName1 = "a.cs";
+            const string fileName2 = "b.cs";
+
+            DynamicExtensionLoaderAccessor extensionLoader = _container.Resolve<DynamicExtensionLoaderAccessor>();
+            StubFileSystem stubFileSystem = _container.Resolve<StubFileSystem>();
+            StubFileSystem.FileEntry fileEntry = stubFileSystem.CreateFileEntry("orchard.a.csjproj");
+
+            // Create duplicate source files (invalid situation in reality but easy enough to test)
+            _mockedStubProjectFileParser.Setup(stubProjectFileParser => stubProjectFileParser.Parse(It.IsAny<Stream>())).Returns(
+                new ProjectFileDescriptor { SourceFilenames = new[] { fileName1, fileName2, fileName1 } }); // duplicate file
+
+            IEnumerable<string> dependencies = extensionLoader.GetDependenciesAccessor(fileEntry.Name);
+
+            Assert.That(dependencies.Count(), Is.EqualTo(3), "3 results should mean no duplicates");
+            Assert.That(dependencies.FirstOrDefault(dep => dep.Equals(fileEntry.Name)), Is.Not.Null);
+            Assert.That(dependencies.FirstOrDefault(dep => dep.Equals(fileName1)), Is.Not.Null);
+            Assert.That(dependencies.FirstOrDefault(dep => dep.Equals(fileName2)), Is.Not.Null);
+        }
+
+        [Test]
+        public void GetDependenciesContainsNoDuplicatesEvenIfMultipleProjectsTest() {
+            const string fileName1 = "a.cs";
+            const string fileName2 = "b.cs";
+
+            const string commonFileName = "c.cs";
+
+            DynamicExtensionLoaderAccessor extensionLoader = _container.Resolve<DynamicExtensionLoaderAccessor>();
+            StubFileSystem stubFileSystem = _container.Resolve<StubFileSystem>();
+            StubFileSystem.FileEntry fileEntry = stubFileSystem.CreateFileEntry("orchard.a.csjproj");
+            StubFileSystem.FileEntry fileEntry2 = stubFileSystem.CreateFileEntry("orchard.b.csjproj");
+            StubFileSystem.FileEntry fileEntry3 = stubFileSystem.CreateFileEntry("orchard.c.csjproj");
+
+            // Project a reference b and c which share a file in common
+
+            // Result for project a
+            _mockedStubProjectFileParser.Setup(stubProjectFileParser => stubProjectFileParser.Parse(It.Is<Stream>(stream => ((StubFileSystem.FileEntryReadStream)stream).FileEntry == fileEntry)))
+                .Returns(
+                    new ProjectFileDescriptor {
+                        SourceFilenames = new[] { fileName1, fileName2 },
+                        References = new[] { 
+                            new ReferenceDescriptor {
+                                ReferenceType = ReferenceType.Project,
+                                SimpleName = Path.GetFileNameWithoutExtension(fileEntry2.Name),
+                                FullName = Path.GetFileNameWithoutExtension(fileEntry2.Name),
+                                Path = fileEntry2.Name
+                            },
+                            new ReferenceDescriptor {
+                                ReferenceType = ReferenceType.Project,
+                                SimpleName = Path.GetFileNameWithoutExtension(fileEntry2.Name),
+                                FullName = Path.GetFileNameWithoutExtension(fileEntry2.Name),
+                                Path = fileEntry3.Name
+                            }
+                        }
+                    });
+
+            // Result for project b and c
+            _mockedStubProjectFileParser.Setup(stubProjectFileParser => stubProjectFileParser.Parse(It.Is<Stream>(stream =>
+                ((StubFileSystem.FileEntryReadStream)stream).FileEntry == fileEntry2 || ((StubFileSystem.FileEntryReadStream)stream).FileEntry == fileEntry3)))
+                .Returns(
+                    new ProjectFileDescriptor {
+                        SourceFilenames = new[] { commonFileName }
+                    });
+
+            IEnumerable<string> dependencies = extensionLoader.GetDependenciesAccessor(fileEntry.Name);
+
+            Assert.That(dependencies.Count(), Is.EqualTo(6), "6 results should mean no duplicates");
+
+            // Project files
+            Assert.That(dependencies.FirstOrDefault(dep => dep.Equals(fileEntry.Name)), Is.Not.Null);
+            Assert.That(dependencies.FirstOrDefault(dep => dep.Equals(fileEntry2.Name)), Is.Not.Null);
+            Assert.That(dependencies.FirstOrDefault(dep => dep.Equals(fileEntry3.Name)), Is.Not.Null);
+
+            // Individual source files
+            Assert.That(dependencies.FirstOrDefault(dep => dep.Equals(fileName1)), Is.Not.Null);
+            Assert.That(dependencies.FirstOrDefault(dep => dep.Equals(fileName2)), Is.Not.Null);
+            Assert.That(dependencies.FirstOrDefault(dep => dep.Equals(commonFileName)), Is.Not.Null);
+        }
+
+        [Test]
+        public void GetDependenciesContainsBinForReferencedProjectsTest() {
+            const string fileName1 = "a.cs";
+            const string fileName2 = "b.cs";
+
+            const string commonFileName = "c.cs";
+
+            DynamicExtensionLoaderAccessor extensionLoader = _container.Resolve<DynamicExtensionLoaderAccessor>();
+            StubFileSystem stubFileSystem = _container.Resolve<StubFileSystem>();
+            StubFileSystem.FileEntry fileEntry = stubFileSystem.CreateFileEntry("orchard.a.csjproj");
+            StubFileSystem.FileEntry fileEntry2 = stubFileSystem.CreateFileEntry("orchard.b.csjproj");
+
+            StubFileSystem.DirectoryEntry directoryEntry = stubFileSystem.CreateDirectoryEntry("bin");
+            StubFileSystem.FileEntry fileEntry3 = directoryEntry.CreateFile("orchard.b.dll");
+
+            // Project a reference b and c which share a file in common
+
+            // Result for project a
+            _mockedStubProjectFileParser.Setup(stubProjectFileParser => stubProjectFileParser.Parse(It.Is<Stream>(stream => ((StubFileSystem.FileEntryReadStream)stream).FileEntry == fileEntry)))
+                .Returns(
+                    new ProjectFileDescriptor {
+                        SourceFilenames = new[] { fileName1, fileName2 },
+                        References = new[] { 
+                            new ReferenceDescriptor {
+                                ReferenceType = ReferenceType.Project,
+                                SimpleName = Path.GetFileNameWithoutExtension(fileEntry2.Name),
+                                FullName = Path.GetFileNameWithoutExtension(fileEntry2.Name),
+                                Path = fileEntry2.Name
+                            }
+                        }
+                    });
+
+            // Result for project b and c
+            _mockedStubProjectFileParser.Setup(stubProjectFileParser => stubProjectFileParser.Parse(It.Is<Stream>(stream =>
+                ((StubFileSystem.FileEntryReadStream)stream).FileEntry == fileEntry2)))
+                .Returns(
+                    new ProjectFileDescriptor {
+                        SourceFilenames = new[] { commonFileName }
+                    });
+
+            _mockedDependenciesFolder.Setup(dependenciesFolder => dependenciesFolder.GetDescriptor(It.Is<string>(moduleName => moduleName == Path.GetDirectoryName(fileEntry2.Name))))
+                .Returns(
+                    new DependencyDescriptor {
+                        VirtualPath = Path.Combine(directoryEntry.Name, fileEntry3.Name)
+                    });
+
+            IEnumerable<string> dependencies = extensionLoader.GetDependenciesAccessor(fileEntry.Name);
+
+            Assert.That(dependencies.Count(), Is.EqualTo(6), "6 results should mean no duplicates");
+
+            // Project files
+            Assert.That(dependencies.FirstOrDefault(dep => dep.Equals(fileEntry.Name)), Is.Not.Null);
+            Assert.That(dependencies.FirstOrDefault(dep => dep.Equals(fileEntry2.Name)), Is.Not.Null);
+            Assert.That(dependencies.FirstOrDefault(dep => dep.Equals(Path.Combine(directoryEntry.Name, fileEntry3.Name))), Is.Not.Null);
+
+            // Individual source files
+            Assert.That(dependencies.FirstOrDefault(dep => dep.Equals(fileName1)), Is.Not.Null);
+            Assert.That(dependencies.FirstOrDefault(dep => dep.Equals(fileName2)), Is.Not.Null);
+            Assert.That(dependencies.FirstOrDefault(dep => dep.Equals(commonFileName)), Is.Not.Null);
+        }
+
+        internal class DynamicExtensionLoaderAccessor : DynamicExtensionLoader {
+            public DynamicExtensionLoaderAccessor(
+                IBuildManager buildManager,
+                IVirtualPathProvider virtualPathProvider,
+                IVirtualPathMonitor virtualPathMonitor,
+                IHostEnvironment hostEnvironment,
+                IAssemblyProbingFolder assemblyProbingFolder,
+                IDependenciesFolder dependenciesFolder,
+                IProjectFileParser projectFileParser)
+                : base(buildManager, virtualPathProvider, virtualPathMonitor, hostEnvironment, assemblyProbingFolder, dependenciesFolder, projectFileParser) {}
+
+            public IEnumerable<string> GetDependenciesAccessor(string projectPath) {
+                return GetDependencies(projectPath);
+            }
+        }
+    }
+}
diff --git a/src/Orchard.Tests/Orchard.Framework.Tests.csproj b/src/Orchard.Tests/Orchard.Framework.Tests.csproj
index 57f4a1b23..cc6d269b4 100644
--- a/src/Orchard.Tests/Orchard.Framework.Tests.csproj
+++ b/src/Orchard.Tests/Orchard.Framework.Tests.csproj
@@ -235,6 +235,7 @@
     <Compile Include="Environment\DefaultWorkContextAccessorTests.cs" />
     <Compile Include="Environment\Extensions\ExtensionLoaderCoordinatorTests.cs" />
     <Compile Include="Environment\Features\FeatureManagerTests.cs" />
+    <Compile Include="Environment\Loaders\DynamicExtensionLoaderTests.cs" />
     <Compile Include="Environment\State\DefaultProcessingEngineTests.cs" />
     <Compile Include="Environment\RunningShellTableTests.cs" />
     <Compile Include="Environment\StubHostEnvironment.cs" />
diff --git a/src/Orchard.Tests/Stubs/StubFileSystem.cs b/src/Orchard.Tests/Stubs/StubFileSystem.cs
index 7234b24e0..b6bda00f8 100644
--- a/src/Orchard.Tests/Stubs/StubFileSystem.cs
+++ b/src/Orchard.Tests/Stubs/StubFileSystem.cs
@@ -228,6 +228,8 @@ namespace Orchard.Tests.Stubs {
                 _clock = clock;
             }
 
+            public FileEntry FileEntry { get { return _entry; } }
+
             public override void Flush() {
                 throw new NotImplementedException();
             }
diff --git a/src/Orchard/Environment/Extensions/Loaders/DynamicExtensionLoader.cs b/src/Orchard/Environment/Extensions/Loaders/DynamicExtensionLoader.cs
index 64dcdebc0..28ecf38a8 100644
--- a/src/Orchard/Environment/Extensions/Loaders/DynamicExtensionLoader.cs
+++ b/src/Orchard/Environment/Extensions/Loaders/DynamicExtensionLoader.cs
@@ -18,6 +18,7 @@ namespace Orchard.Environment.Extensions.Loaders {
         private readonly IVirtualPathMonitor _virtualPathMonitor;
         private readonly IHostEnvironment _hostEnvironment;
         private readonly IAssemblyProbingFolder _assemblyProbingFolder;
+        private readonly IDependenciesFolder _dependenciesFolder;
         private readonly IProjectFileParser _projectFileParser;
         private readonly ReloadWorkaround _reloadWorkaround = new ReloadWorkaround();
 
@@ -37,6 +38,7 @@ namespace Orchard.Environment.Extensions.Loaders {
             _hostEnvironment = hostEnvironment;
             _assemblyProbingFolder = assemblyProbingFolder;
             _projectFileParser = projectFileParser;
+            _dependenciesFolder = dependenciesFolder;
 
             Logger = NullLogger.Instance;
         }
@@ -176,34 +178,48 @@ namespace Orchard.Environment.Extensions.Loaders {
             };
         }
 
-        private IEnumerable<string> GetDependencies(string projectPath) {
-            List<string> dependencies = new[] { projectPath }.ToList();
+        protected IEnumerable<string> GetDependencies(string projectPath) {
+            HashSet<string> dependencies = new HashSet<string> { projectPath };
 
-            var basePath = _virtualPathProvider.GetDirectoryName(projectPath);
+            AddDependencies(projectPath, dependencies);
+
+            return dependencies;
+        }
+
+        private void AddDependencies(string projectPath, HashSet<string> currentSet) {
+            string basePath = _virtualPathProvider.GetDirectoryName(projectPath);
 
             using (var stream = _virtualPathProvider.OpenFile(projectPath)) {
-                var projectFile = _projectFileParser.Parse(stream);
+                ProjectFileDescriptor projectFile = _projectFileParser.Parse(stream);
 
                 // Add source files
-                dependencies.AddRange(projectFile.SourceFilenames.Select(f => _virtualPathProvider.Combine(basePath, f)));
+                currentSet.UnionWith(projectFile.SourceFilenames.Select(f => _virtualPathProvider.Combine(basePath, f)));
 
-                // Add Project and Library References
-                foreach (ReferenceDescriptor referenceDescriptor in projectFile.References.Where(reference => !string.IsNullOrEmpty(reference.Path))) {
-                    string path = referenceDescriptor.ReferenceType == ReferenceType.Library
-                        ? _virtualPathProvider.GetProjectReferenceVirtualPath(projectPath, referenceDescriptor.SimpleName, referenceDescriptor.Path)
-                        : _virtualPathProvider.Combine(basePath, referenceDescriptor.Path);
+                // Add Project and Library references
+                if (projectFile.References != null) {
+                    foreach (ReferenceDescriptor referenceDescriptor in projectFile.References.Where(reference => !string.IsNullOrEmpty(reference.Path))) {
+                        string path = referenceDescriptor.ReferenceType == ReferenceType.Library
+                                          ? _virtualPathProvider.GetProjectReferenceVirtualPath(projectPath, referenceDescriptor.SimpleName, referenceDescriptor.Path)
+                                          : _virtualPathProvider.Combine(basePath, referenceDescriptor.Path);
 
-                    if (_virtualPathProvider.FileExists(path)) {
-                        dependencies.Add(path);
+                        // Attempt to reference the project / library file
+                        if (!currentSet.Contains(path) && _virtualPathProvider.FileExists(path)) {
+                            currentSet.Add(path);
 
-                        if (referenceDescriptor.ReferenceType == ReferenceType.Project) {
-                            dependencies.AddRange(GetDependencies(path));
+                            // In case of project, also reference the source files
+                            if (referenceDescriptor.ReferenceType == ReferenceType.Project) {
+                                AddDependencies(path, currentSet);
+
+                                // Try to also reference any pre-built DLL
+                                DependencyDescriptor dependencyDescriptor = _dependenciesFolder.GetDescriptor(_virtualPathProvider.GetDirectoryName(referenceDescriptor.Path));
+                                if (dependencyDescriptor != null && _virtualPathProvider.FileExists(dependencyDescriptor.VirtualPath)) {
+                                    currentSet.Add(dependencyDescriptor.VirtualPath);
+                                }
+                            }
                         }
                     }
                 }
             }
-
-            return dependencies;
         }
 
         private string GetProjectPath(ExtensionDescriptor descriptor) {
@@ -226,7 +242,7 @@ namespace Orchard.Environment.Extensions.Loaders {
         /// The purpose of this class is to keep track of all .csproj files monitored until
         /// an AppDomain restart.
         /// </summary>
-        class ReloadWorkaround {
+        internal class ReloadWorkaround {
             private readonly List<IVolatileToken> _tokens = new List<IVolatileToken>();
 
             public void Monitor(IVolatileToken whenProjectFileChanges) {