diff --git a/test/BB2B_Test.cc b/test/BB2B_Test.cc
index 31438d9..91d41b1 100644
--- a/test/BB2B_Test.cc
+++ b/test/BB2B_Test.cc
@@ -30,5 +30,10 @@ TEST(BB2B, Basics) {
 
   float leftMotorSpeed = obstacleRight ? -1.0F : 1.0F;
   float rightMotorSpeed = obstacleLeft ? -1.0F : 1.0F;
+
+  DifferentialDrive *diffDrive = (DifferentialDrive *)&roboid->propulsion;
+  diffDrive->SetTargetSpeeds(leftMotorSpeed, rightMotorSpeed);
+
+  // cannot chek verlocity in this branch?
 }
 #endif