diff --git a/Framework/Tracking/BlobStorageClient.cs b/Framework/Tracking/BlobStorageClient.cs
index 5b198aba7..53143c62f 100644
--- a/Framework/Tracking/BlobStorageClient.cs
+++ b/Framework/Tracking/BlobStorageClient.cs
@@ -27,11 +27,11 @@ namespace DurableTask.Tracking
     /// </summary>
     public class BlobStorageClient
     {
-        // use hubName as the container prefix. 
-        // the container full name is in the format of {hubName}-{streamType}-{DateTime};
+        // container prefix is in the format of {hubName}-dtfx. It is not part of the blob storage key.
+        // the container full name is in the format of {hubName}-dtfx-{streamType}-{DateTime};
         // the streamType is the type of the stream, either 'message' or 'session';
         // the date time is in the format of yyyyMMdd.
-        readonly string hubName;
+        readonly string containerNamePrefix;
         readonly CloudBlobClient blobClient;
 
         const int MaxRetries = 3;
@@ -59,9 +59,9 @@ public BlobStorageClient(string hubName, string connectionString)
             this.blobClient.DefaultRequestOptions.RetryPolicy = new ExponentialRetry(DeltaBackOff, MaxRetries);
             this.blobClient.DefaultRequestOptions.MaximumExecutionTime = MaximumExecutionTime;
 
-            // save the lower case since it will be used as the prefix of the container name,
+            // make the hub name lower case since it will be used as part of the prefix of the container name,
             // which only allows lower case letters
-            this.hubName = hubName.ToLower();
+            this.containerNamePrefix = BlobStorageClientHelper.BuildContainerNamePrefix(hubName.ToLower());
         }
 
         /// <summary>
@@ -99,19 +99,19 @@ public async Task<Stream> DownloadStreamAsync(string key)
 
         async Task<ICloudBlob> GetCloudBlockBlobReferenceAsync(string containerNameSuffix, string blobName)
         {
-            string containerName = BlobStorageClientHelper.BuildContainerName(hubName, containerNameSuffix);
+            string containerName = BlobStorageClientHelper.BuildContainerName(this.containerNamePrefix, containerNameSuffix);
             var cloudBlobContainer = this.blobClient.GetContainerReference(containerName);
             await cloudBlobContainer.CreateIfNotExistsAsync();
             return cloudBlobContainer.GetBlockBlobReference(blobName);
         }
 
         /// <summary>
-        /// List all containers of the blob storage, whose prefix is hub name.
+        /// List all containers of the blob storage, whose prefix is containerNamePrefix, i.e., {hubName}-dtfx.
         /// </summary>
         /// <returns>A list of Azure blob containers</returns>
         public IEnumerable<CloudBlobContainer> ListContainers()
         {
-            return this.blobClient.ListContainers(this.hubName);
+            return this.blobClient.ListContainers(this.containerNamePrefix);
         }
 
         /// <summary>
@@ -127,7 +127,7 @@ public async Task DeleteExpiredContainersAsync(DateTime thresholdDateTimeUtc)
         }
 
         /// <summary>
-        /// Delete blob containers with the hub name as prefix.
+        /// Delete blob containers with the containerNamePrefix as prefix.
         /// </summary>
         /// <returns></returns>
         public async Task DeleteBlobStoreContainersAsync()
diff --git a/Framework/Tracking/BlobStorageClientHelper.cs b/Framework/Tracking/BlobStorageClientHelper.cs
index b1e798f36..4388f1fe7 100644
--- a/Framework/Tracking/BlobStorageClientHelper.cs
+++ b/Framework/Tracking/BlobStorageClientHelper.cs
@@ -61,6 +61,18 @@ static string BuildContainerNameSuffix(string containerType, DateTime blobCreati
             return $"{containerType.ToLower()}{ContainerNameDelimiter}{GetDateStringForContainerName(blobCreationTime)}";
         }
 
+        /// <summary>
+        /// Build the container name prefix using the lower case hub name.
+        /// It is in the format of {hubName}-dtfx.
+        /// The container name prefix is not part of the generated storage key.
+        /// </summary>
+        /// <param name="hubName">The hub name. Converted to lower case to build the prefix.</param>
+        /// <returns>The container name prefix</returns>
+        public static string BuildContainerNamePrefix(string hubName)
+        {
+            return $"{hubName.ToLower()}{ContainerNameDelimiter}dtfx";
+        }
+
         /// <summary>
         /// Build a storage key for the session.
         /// </summary>
@@ -98,7 +110,7 @@ public static void ParseKey(string key, out string containerNameSuffix, out stri
             string[] segments = key.Split(new[] {BlobStorageClientHelper.KeyDelimiter}, 2);
             if (segments.Length < 2)
             {
-                throw new ArgumentException("storage key {key} does not contain required 2 or more segments: containerNameSuffix|blobName.", nameof(key));
+                throw new ArgumentException($"storage key {key} does not contain required 2 or more segments: containerNameSuffix|blobName.", nameof(key));
             }
 
             containerNameSuffix = segments[0];
@@ -134,11 +146,11 @@ static bool IsValidContainerNameSuffix(string containerNameSuffix)
         public static bool IsContainerExpired(string containerName, DateTime thresholdDateTimeUtc)
         {
             string[] segments = containerName.Split(ContainerNameDelimiter);
-            if (segments.Length != 3)
+            if (segments.Length != 4)
             {
                 TraceHelper.Trace(
                     TraceEventType.Warning,
-                    $"container name {containerName} does not contain required 3 segments.");
+                    $"container name {containerName} does not contain required 4 segments.");
 
                 return false;
             }
diff --git a/FrameworkUnitTests/BlobStorageClientHelperTest.cs b/FrameworkUnitTests/BlobStorageClientHelperTest.cs
index d547b4105..23a8c4b9e 100644
--- a/FrameworkUnitTests/BlobStorageClientHelperTest.cs
+++ b/FrameworkUnitTests/BlobStorageClientHelperTest.cs
@@ -26,14 +26,14 @@ public void IsContainerExpiredTest()
         {
             Assert.AreEqual("ab-cd", BlobStorageClientHelper.BuildContainerName("ab", "cd"));
 
-            Assert.IsTrue(BlobStorageClientHelper.IsContainerExpired("hubName-message-20100101", DateTime.UtcNow));
-            Assert.IsFalse(BlobStorageClientHelper.IsContainerExpired("hubName-session-20990101", DateTime.UtcNow));
+            Assert.IsTrue(BlobStorageClientHelper.IsContainerExpired("hubname-dtfx-message-20100101", DateTime.UtcNow));
+            Assert.IsFalse(BlobStorageClientHelper.IsContainerExpired("hubname-dtfx-session-20990101", DateTime.UtcNow));
 
             DateTime dateTime = new DateTime(2015, 05, 17);
-            Assert.IsTrue(BlobStorageClientHelper.IsContainerExpired("hubName-message-20150516", dateTime));
-            Assert.IsFalse(BlobStorageClientHelper.IsContainerExpired("hubName-message-20150517", dateTime));
-            Assert.IsFalse(BlobStorageClientHelper.IsContainerExpired("hubName-message-20150518", dateTime));
-            Assert.IsTrue(BlobStorageClientHelper.IsContainerExpired("hubName-message-20140518", dateTime));
+            Assert.IsTrue(BlobStorageClientHelper.IsContainerExpired("hubname-dtfx-message-20150516", dateTime));
+            Assert.IsFalse(BlobStorageClientHelper.IsContainerExpired("hubname-dtfx-message-20150517", dateTime));
+            Assert.IsFalse(BlobStorageClientHelper.IsContainerExpired("hubname-dtfx-message-20150518", dateTime));
+            Assert.IsTrue(BlobStorageClientHelper.IsContainerExpired("hubname-dtfx-message-20140518", dateTime));
 
             // invalid containers are ignored
             Assert.IsFalse(BlobStorageClientHelper.IsContainerExpired("invalidContainerName", DateTime.UtcNow));
@@ -63,6 +63,14 @@ public void BuildSessionStorageKeyTest()
             Assert.IsTrue(regex.Match(key).Success);
         }
 
+        [TestMethod]
+        public void BuildContainerNamePrefixTest()
+        {
+            string hubName = "HubName";
+            string containerNamePrefix = BlobStorageClientHelper.BuildContainerNamePrefix(hubName);
+            Assert.AreEqual("hubname-dtfx", containerNamePrefix);
+        }
+
         [TestMethod]
         public void ParseKeyTest()
         {
@@ -92,7 +100,7 @@ public void ParseKeyTest()
             }
             catch (ArgumentException e)
             {
-                Assert.IsTrue(e.Message.Contains("containerNameSuffix"), "Exception must contain containerNameSuffix.");
+                Assert.IsTrue(e.Message.Contains("Message-20100319"), "Exception must contain the invalid container name suffix.");
             }
         }
     }