diff --git a/src/Blob/Controllers/BlobController.cs b/src/Blob/Controllers/BlobController.cs
index eb0b405b6086df411982a53174154fc01d608e2a..f42a992984d0ab1edf50e219884c71efe6357f99 100644
--- a/src/Blob/Controllers/BlobController.cs
+++ b/src/Blob/Controllers/BlobController.cs
@@ -1,3 +1,4 @@
+using Coscine.Api.Blob.Util;
 using Coscine.ApiCommons;
 using Coscine.Configuration;
 using Coscine.Database.DataModel;
@@ -66,7 +67,7 @@ namespace Coscine.Api.Blob.Controllers
         /// <returns> Uri </returns>
         public Uri GenerateId(string resourceId, string path)
         {
-            return new Uri($"https://hdl.handle.net/{_prefix}/{resourceId}@path={Uri.EscapeDataString(path)}");
+            return new CustomUri($"https://hdl.handle.net/{_prefix}/{resourceId}@path={Uri.EscapeDataString(path)}");
         }
 
         /// <summary>
@@ -290,7 +291,7 @@ namespace Coscine.Api.Blob.Controllers
             }
 
             var id = GenerateId(resourceId, path);
-            if (!_rdfStoreConnector.HasGraph(id.AbsoluteUri))
+            if (!_rdfStoreConnector.HasGraph(id))
             {
                 return StatusCode((int)HttpStatusCode.Forbidden,
                     "No metadata set has been added for this file.");
diff --git a/src/Blob/Util/CustomUri.cs b/src/Blob/Util/CustomUri.cs
new file mode 100644
index 0000000000000000000000000000000000000000..1dfec1983a109c920320f1c7d8835daa3ace0666
--- /dev/null
+++ b/src/Blob/Util/CustomUri.cs
@@ -0,0 +1,28 @@
+using System;
+
+namespace Coscine.Api.Blob.Util
+{
+    /// <summary>
+    /// Adapts the returned ToString of a Uri
+    /// </summary>
+    public class CustomUri : Uri
+    {
+        /// <summary>
+        /// Constructs a Custom Uri
+        /// </summary>
+        /// <param name="uri"></param>
+        public CustomUri(string uri) : base(uri)
+        {
+
+        }
+
+        /// <summary>
+        /// Overwrites the ToString for returning the AbsoluteUri (for dotNetRDF)
+        /// </summary>
+        /// <returns></returns>
+        public override string ToString()
+        {
+            return AbsoluteUri;
+        }
+    }
+}