diff --git a/tests/SampleTool/CrashCommand.cs b/tests/SampleTool/CrashCommand.cs
index 51b2efb..8654510 100644
--- a/tests/SampleTool/CrashCommand.cs
+++ b/tests/SampleTool/CrashCommand.cs
@@ -21,6 +21,12 @@ namespace SampleTool
             this.AddOption(this.messyOption);
         }
 
+        /// <inheritdoc />
+        public int Invoke(InvocationContext context)
+        {
+            return this.InvokeAsync(context).Result;
+        }
+
         /// <inheritdoc />
         public Task<int> InvokeAsync(InvocationContext context)
         {
diff --git a/tests/SampleTool/LogCommand.cs b/tests/SampleTool/LogCommand.cs
index 45bda7a..e72e07f 100644
--- a/tests/SampleTool/LogCommand.cs
+++ b/tests/SampleTool/LogCommand.cs
@@ -25,6 +25,12 @@ public class LogCommand : Command, ICommandHandler
         this.Handler = this;
     }
 
+    /// <inheritdoc />
+    public int Invoke(InvocationContext context)
+    {
+        return this.InvokeAsync(context).Result;
+    }
+
     /// <inheritdoc />
     public Task<int> InvokeAsync(InvocationContext context)
     {
diff --git a/tests/SampleTool/TableCommand.cs b/tests/SampleTool/TableCommand.cs
index 193bdea..e8a2db7 100644
--- a/tests/SampleTool/TableCommand.cs
+++ b/tests/SampleTool/TableCommand.cs
@@ -39,6 +39,12 @@ namespace SampleTool
             this.Handler = this;
         }
 
+        /// <inheritdoc />
+        public int Invoke(InvocationContext context)
+        {
+            return this.InvokeAsync(context).Result;
+        }
+
         /// <inheritdoc />
         public Task<int> InvokeAsync(InvocationContext context)
         {