diff --git a/src/Orchard.Web/Modules/Orchard.OutputCache/Filters/OutputCacheFilter.cs b/src/Orchard.Web/Modules/Orchard.OutputCache/Filters/OutputCacheFilter.cs
index 4e0bc04a3..e79eef985 100644
--- a/src/Orchard.Web/Modules/Orchard.OutputCache/Filters/OutputCacheFilter.cs
+++ b/src/Orchard.Web/Modules/Orchard.OutputCache/Filters/OutputCacheFilter.cs
@@ -41,6 +41,7 @@ namespace Orchard.OutputCache.Filters {
         private readonly ICacheService _cacheService;
         private readonly ISignals _signals;
         private readonly ShellSettings _shellSettings;
+        private readonly ICachingEventHandler _chachingEvents;
         private bool _isDisposed = false;
 
         public ILogger Logger { get; set; }
@@ -55,7 +56,8 @@ namespace Orchard.OutputCache.Filters {
             IClock clock,
             ICacheService cacheService,
             ISignals signals,
-            ShellSettings shellSettings) {
+            ShellSettings shellSettings,
+            ICachingEventHandler chachingEvents) {
 
             _cacheManager = cacheManager;
             _cacheStorageProvider = cacheStorageProvider;
@@ -67,6 +69,7 @@ namespace Orchard.OutputCache.Filters {
             _cacheService = cacheService;
             _signals = signals;
             _shellSettings = shellSettings;
+            _chachingEvents = chachingEvents;
 
             Logger = NullLogger.Instance;
         }
@@ -616,6 +619,14 @@ namespace Orchard.OutputCache.Filters {
                 }
             }
 
+            //make CacheKey morphable by external modules
+            try {
+                keyBuilder = _chachingEvents.ParticipateInCacheKey(keyBuilder);
+            } catch (UnauthorizedAccessException ex) {
+                throw new UnauthorizedAccessException();
+            } catch { }
+
+
             return keyBuilder.ToString();
         }
 
diff --git a/src/Orchard.Web/Modules/Orchard.OutputCache/ICachingEventHandler.cs b/src/Orchard.Web/Modules/Orchard.OutputCache/ICachingEventHandler.cs
new file mode 100644
index 000000000..6e9aebf5a
--- /dev/null
+++ b/src/Orchard.Web/Modules/Orchard.OutputCache/ICachingEventHandler.cs
@@ -0,0 +1,12 @@
+using Orchard.Events;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Web;
+
+namespace Orchard.OutputCache {
+    public interface ICachingEventHandler : IEventHandler {
+        StringBuilder ParticipateInCacheKey(StringBuilder key);
+    }
+}
\ No newline at end of file
diff --git a/src/Orchard.Web/Modules/Orchard.OutputCache/Orchard.OutputCache.csproj b/src/Orchard.Web/Modules/Orchard.OutputCache/Orchard.OutputCache.csproj
index a3a7fa74c..9a4520288 100644
--- a/src/Orchard.Web/Modules/Orchard.OutputCache/Orchard.OutputCache.csproj
+++ b/src/Orchard.Web/Modules/Orchard.OutputCache/Orchard.OutputCache.csproj
@@ -103,6 +103,7 @@
     <Content Include="Web.config" />
     <Content Include="Scripts\Web.config" />
     <Content Include="Styles\Web.config" />
+    <Compile Include="ICachingEventHandler.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Content Include="Module.txt" />
   </ItemGroup>
diff --git a/src/Orchard/Data/Migration/AutomaticDataMigrations.cs b/src/Orchard/Data/Migration/AutomaticDataMigrations.cs
index fb5a3456c..2c936313a 100644
--- a/src/Orchard/Data/Migration/AutomaticDataMigrations.cs
+++ b/src/Orchard/Data/Migration/AutomaticDataMigrations.cs
@@ -80,12 +80,25 @@ namespace Orchard.Data.Migration {
         /// <summary>
         /// This ensures that the framework migrations have run for the distributed locking feature, as existing Orchard installations will not have the required tables when upgrading.
         /// </summary>
-        private void EnsureDistributedLockSchemaExists() {
+        private void EnsureDistributedLockSchemaExists()
+        {
             // Ensure the distributed lock record schema exists.
             var schemaBuilder = new SchemaBuilder(_dataMigrationInterpreter);
             var distributedLockSchemaBuilder = new DistributedLockSchemaBuilder(_shellSettings, schemaBuilder);
-            if (distributedLockSchemaBuilder.EnsureSchema())
+            if (!distributedLockSchemaBuilder.SchemaExists())
+            {
+
+                // Workaround to avoid some Transaction issue for PostgreSQL.
+                if (_shellSettings.DataProvider.Equals("PostgreSql", StringComparison.OrdinalIgnoreCase))
+                {
+                    _transactionManager.RequireNew();
+                    distributedLockSchemaBuilder.CreateSchema();
+                    return;
+                }
+
+                distributedLockSchemaBuilder.CreateSchema();
                 _transactionManager.RequireNew();
+            }
         }
     }
 }