diff --git a/com.unity.ml-agents/Tests/Editor/Sensor/SensorShapeValidatorTests.cs b/com.unity.ml-agents/Tests/Editor/Sensor/SensorShapeValidatorTests.cs
index 77d619f284..a9d9bf093e 100644
--- a/com.unity.ml-agents/Tests/Editor/Sensor/SensorShapeValidatorTests.cs
+++ b/com.unity.ml-agents/Tests/Editor/Sensor/SensorShapeValidatorTests.cs
@@ -2,6 +2,7 @@
 using NUnit.Framework;
 using UnityEngine;
 using UnityEngine.TestTools;
+using MLAgents.Sensors;
 
 namespace MLAgents.Tests
 {