diff --git a/VmcMessages/VmcExtSetCalibExec.cs b/VmcMessages/VmcExtSetCalibExec.cs
index 4c5d498..39ce878 100644
--- a/VmcMessages/VmcExtSetCalibExec.cs
+++ b/VmcMessages/VmcExtSetCalibExec.cs
@@ -18,6 +18,7 @@
 
 using Godot;
 using godotOscSharp;
+using System.Collections.Generic;
 
 namespace godotVmcSharp
 {