diff --git a/robot_skills/src/robot_skills/mockbot.py b/robot_skills/src/robot_skills/mockbot.py
index 027326f42..9ca508600 100755
--- a/robot_skills/src/robot_skills/mockbot.py
+++ b/robot_skills/src/robot_skills/mockbot.py
@@ -180,6 +180,7 @@ def __init__(self, robot_name, tf_buffer, *args, **kwargs):
 class GripperPositionDetector(MockedRobotPart):
     def __init__(self, robot_name, tf_buffer, *args, **kwargs):
         super(GripperPositionDetector, self).__init__(robot_name, tf_buffer)
+        self.minimum_position = -0.75
         self.detect = AlteredMagicMock(return_value=0.0)