diff --git a/src/WebJobs.Extensions.DurableTask/ContextInterfaces/IDurableOrchestrationClient.cs b/src/WebJobs.Extensions.DurableTask/ContextInterfaces/IDurableOrchestrationClient.cs
index ddf1e234b..94b4f0f0c 100644
--- a/src/WebJobs.Extensions.DurableTask/ContextInterfaces/IDurableOrchestrationClient.cs
+++ b/src/WebJobs.Extensions.DurableTask/ContextInterfaces/IDurableOrchestrationClient.cs
@@ -141,8 +141,7 @@ Task<string> StartNewAsync(
         /// </exception>
         Task<string> StartNewAsync<T>(
             string orchestratorFunctionName,
-            T input)
-            where T : class;
+            T input);
 
         /// <summary>
         /// Starts a new instance of the specified orchestrator function.