diff --git a/CombinedResourceManager.cs b/CombinedResourceManager.cs
index 473185f..eda457c 100644
--- a/CombinedResourceManager.cs
+++ b/CombinedResourceManager.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text.RegularExpressions;
-using Autofac.Features.Metadata;
-using Orchard.Caching;
+using Autofac.Features.Metadata;
 using Orchard.ContentManagement; // For generic ContentManager methods
 using Orchard.DisplayManagement.Descriptors;
 using Orchard.DisplayManagement.Descriptors.ResourceBindingStrategy;
@@ -13,12 +9,14 @@
 using Orchard.Settings;
 using Orchard.Themes;
 using Orchard.UI.Resources;
-using Piedone.Combinator.EventHandlers;
 using Piedone.Combinator.Extensions;
 using Piedone.Combinator.Models;
 using Piedone.Combinator.Services;
-using System.Linq;
 using Piedone.HelpfulLibraries.Utilities;
+using System;
+using System.Collections.Generic;
+using System.Text.RegularExpressions;
+using System.Threading;
 
 namespace Piedone.Combinator
 {
@@ -105,9 +103,21 @@ public override IList<ResourceRequiredContext> BuildRequiredResources(string str
 
                 IList<ResourceRequiredContext> result;
 
-                if (resourceType == ResourceType.Style) result = _combinatorService.CombineStylesheets(resources, settings);
-                else if (resourceType == ResourceType.JavaScript) result = _combinatorService.CombineScripts(resources, settings);
-                else return base.BuildRequiredResources(stringResourceType);
+                using (var mutex = new Mutex(initiallyOwned: false, "Global\\CombinatorFileAccess"))
+                {
+                    mutex.WaitOne();
+
+                    try
+                    {
+                        if (resourceType == ResourceType.Style) result = _combinatorService.CombineStylesheets(resources, settings);
+                        else if (resourceType == ResourceType.JavaScript) result = _combinatorService.CombineScripts(resources, settings);
+                        else return base.BuildRequiredResources(stringResourceType);
+                    }
+                    finally
+                    {
+                        mutex.ReleaseMutex();
+                    }
+                }
 
                 RemoveOriginalResourceShapes(result, resourceType);
 
diff --git a/Services/CacheFileService.cs b/Services/CacheFileService.cs
index 1e42bdb..5194964 100644
--- a/Services/CacheFileService.cs
+++ b/Services/CacheFileService.cs
@@ -1,22 +1,20 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading;
+using Autofac;
 using Orchard;
 using Orchard.Caching;
 using Orchard.Data;
 using Orchard.Environment;
 using Orchard.Environment.Configuration;
 using Orchard.Environment.Extensions;
-using Orchard.Exceptions;
 using Orchard.FileSystems.Media;
-using Orchard.Mvc;
 using Orchard.Services;
 using Piedone.Combinator.EventHandlers;
 using Piedone.Combinator.Extensions;
 using Piedone.Combinator.Models;
-using Autofac;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading;
 using System.Web.Mvc;
 
 namespace Piedone.Combinator.Services
@@ -111,11 +109,23 @@ public void Save(string fingerprint, CombinatorResource resource, ICombinatorSet
 
                 if (_storageProvider.FileExists(path)) _storageProvider.DeleteFile(path);
 
-                using (var stream = _storageProvider.CreateFile(path).OpenWrite())
+                using (var mutex = new Mutex(initiallyOwned: false, "Global\\CombinatorFileAccess"))
                 {
-                    var bytes = Encoding.UTF8.GetBytes(resource.Content);
-                    stream.Write(bytes, 0, bytes.Length);
-                }
+                    mutex.WaitOne();
+
+                    try
+                    {
+                        using (var stream = _storageProvider.CreateFile(path).OpenWrite())
+                        {
+                            var bytes = Encoding.UTF8.GetBytes(resource.Content);
+                            stream.Write(bytes, 0, bytes.Length);
+                        }
+                    }
+                    finally
+                    {
+                        mutex.ReleaseMutex();
+                    }
+                }                
 
                 if (!resource.IsRemoteStorageResource)
                 {
@@ -134,11 +144,23 @@ public void Save(string fingerprint, CombinatorResource resource, ICombinatorSet
                         var relativeUrlsBaseUri = settings.ResourceBaseUri != null ? settings.ResourceBaseUri : new Uri(_urlHelper.RequestContext.HttpContext.Request.Url, _urlHelper.Content("~/"));
                         ResourceProcessingService.RegexConvertRelativeUrlsToAbsolute(testResource, relativeUrlsBaseUri);
 
-                        using (var stream = _storageProvider.CreateFile(path).OpenWrite())
+                        using (var mutex = new Mutex(initiallyOwned: false, "Global\\CombinatorFileAccess"))
                         {
-                            var bytes = Encoding.UTF8.GetBytes(testResource.Content);
-                            stream.Write(bytes, 0, bytes.Length);
-                        }
+                            mutex.WaitOne();
+
+                            try
+                            {
+                                using (var stream = _storageProvider.CreateFile(path).OpenWrite())
+                                {
+                                    var bytes = Encoding.UTF8.GetBytes(testResource.Content);
+                                    stream.Write(bytes, 0, bytes.Length);
+                                }
+                            }
+                            finally
+                            {
+                                mutex.ReleaseMutex();
+                            }
+                        }                        
 
                         resource.IsRemoteStorageResource = true;
                         fileRecord.Settings = _combinatorResourceManager.SerializeResourceSettings(resource);
@@ -238,9 +260,22 @@ public void WriteSpriteStream(string fileName, SpriteStreamWriter streamWriter)
             if (_storageProvider.FileExists(path)) _storageProvider.DeleteFile(path);
             var spriteFile = _storageProvider.CreateFile(path);
             var publicUrl = _storageProvider.GetPublicUrl(path);
-            using (var stream = spriteFile.OpenWrite())
+
+            using (var mutex = new Mutex(initiallyOwned: false, "Global\\CombinatorFileAccess"))
             {
-                streamWriter(stream, publicUrl);
+                mutex.WaitOne();
+
+                try
+                { 
+                    using (var stream = spriteFile.OpenWrite())
+                    {
+                        streamWriter(stream, publicUrl);
+                    }
+                }
+                finally
+                {
+                    mutex.ReleaseMutex();
+                }
             }
         }