diff --git a/apps/operationalSpaceControl/Controller.cpp b/apps/operationalSpaceControl/Controller.cpp
index eec06fcb86804..91736df99c0e3 100644
--- a/apps/operationalSpaceControl/Controller.cpp
+++ b/apps/operationalSpaceControl/Controller.cpp
@@ -50,10 +50,10 @@ Controller::Controller(dart::dynamics::Skeleton* _robot,
 
   mForces.setZero(dof);
 
-  mKp.setZero(dof, dof);
-  mKv.setZero(dof, dof);
+  mKp.setZero();
+  mKv.setZero();
 
-  for (int i = 0; i < dof; ++i)
+  for (int i = 0; i < 3; ++i)
   {
     mKp(i, i) = 750.0;
     mKv(i, i) = 250.0;
diff --git a/apps/operationalSpaceControl/Controller.h b/apps/operationalSpaceControl/Controller.h
index e691f8d78c992..ff3e3e493f42a 100644
--- a/apps/operationalSpaceControl/Controller.h
+++ b/apps/operationalSpaceControl/Controller.h
@@ -75,10 +75,10 @@ class Controller
   Eigen::VectorXd mForces;
 
   /// \brief Proportional gain for the virtual spring forces at the end effector
-  Eigen::MatrixXd mKp;
+  Eigen::Matrix3d mKp;
 
   /// \brief Derivative gain for the virtual spring forces at the end effector
-  Eigen::MatrixXd mKv;
+  Eigen::Matrix3d mKv;
 };
 
 #endif  // APPS_OPERATIONALSPACECONTROL_CONTROLLER_H_