diff --git a/src/DurableTask.Core/Serializing/JsonDataConverter.cs b/src/DurableTask.Core/Serializing/JsonDataConverter.cs
index d3ccbadf4..4e66f5ccd 100644
--- a/src/DurableTask.Core/Serializing/JsonDataConverter.cs
+++ b/src/DurableTask.Core/Serializing/JsonDataConverter.cs
@@ -69,6 +69,12 @@ public override string Serialize(object value)
         /// <returns>Object serialized to a string</returns>
         public override string Serialize(object value, bool formatted)
         {
+            if (value == null)
+            {
+                // This avoids serializing null into "null"
+                return null;
+            }
+
             var sb = new StringBuilder(0x100);
             var textWriter = new StringWriter(sb, CultureInfo.InvariantCulture);
             using (var writer = new JsonTextWriter(textWriter))
diff --git a/tools/DurableTask.props b/tools/DurableTask.props
index 5c24d30de..6935321b4 100644
--- a/tools/DurableTask.props
+++ b/tools/DurableTask.props
@@ -45,9 +45,9 @@
   <!-- Nuget Package Settings -->
   <PropertyGroup>
     <PackageOutputPath>..\..\build_output\packages</PackageOutputPath>
-    <AssemblyVersion>2.4.1</AssemblyVersion>
-    <FileVersion>2.4.1</FileVersion>
-    <Version>2.4.1</Version>
+    <AssemblyVersion>2.4.2</AssemblyVersion>
+    <FileVersion>2.4.2</FileVersion>
+    <Version>2.4.2</Version>
     <Company>Microsoft</Company>
     <Authors>Microsoft</Authors>
     <Product>Durable Task Framework</Product>