diff --git a/src/Orchard.Web/Modules/Orchard.OutputCache/Filters/OutputCacheFilter.cs b/src/Orchard.Web/Modules/Orchard.OutputCache/Filters/OutputCacheFilter.cs
index 8a8871eef..bc2034d39 100644
--- a/src/Orchard.Web/Modules/Orchard.OutputCache/Filters/OutputCacheFilter.cs
+++ b/src/Orchard.Web/Modules/Orchard.OutputCache/Filters/OutputCacheFilter.cs
@@ -33,16 +33,16 @@ namespace Orchard.OutputCache.Filters {
         private static readonly ConcurrentDictionary<string, object> _cacheKeyLocks = new ConcurrentDictionary<string, object>();
 
         // Dependencies.
-        private readonly ICacheManager _cacheManager;
-        private readonly IOutputCacheStorageProvider _cacheStorageProvider;
-        private readonly ITagCache _tagCache;
-        private readonly IDisplayedContentItemHandler _displayedContentItemHandler;
-        private readonly IWorkContextAccessor _workContextAccessor;
-        private readonly IThemeManager _themeManager;
-        private readonly IClock _clock;
-        private readonly ICacheService _cacheService;
-        private readonly ISignals _signals;
-        private readonly ShellSettings _shellSettings;
+        protected readonly ICacheManager _cacheManager;
+        protected readonly IOutputCacheStorageProvider _cacheStorageProvider;
+        protected readonly ITagCache _tagCache;
+        protected readonly IDisplayedContentItemHandler _displayedContentItemHandler;
+        protected readonly IWorkContextAccessor _workContextAccessor;
+        protected readonly IThemeManager _themeManager;
+        protected readonly IClock _clock;
+        protected readonly ICacheService _cacheService;
+        protected readonly ISignals _signals;
+        protected readonly ShellSettings _shellSettings;
         public ILogger Logger { get; set; }
 
         public OutputCacheFilter(