diff --git a/src/sixDoFRigidBodyMotion/sixDoFRigidBodyMotion/sixDoFRigidBodyMotion.C b/src/sixDoFRigidBodyMotion/sixDoFRigidBodyMotion/sixDoFRigidBodyMotion.C
index 78e4c63a85..11a2a21ebf 100644
--- a/src/sixDoFRigidBodyMotion/sixDoFRigidBodyMotion/sixDoFRigidBodyMotion.C
+++ b/src/sixDoFRigidBodyMotion/sixDoFRigidBodyMotion/sixDoFRigidBodyMotion.C
@@ -77,6 +77,7 @@ Foam::sixDoFRigidBodyMotion::sixDoFRigidBodyMotion()
     constraints_(),
     tConstraints_(tensor::I),
     rConstraints_(tensor::I),
+    initialCentreOfMass_(vector::zero),
     initialCentreOfRotation_(vector::zero),
     initialQ_(I),
     mass_(VSMALL),
@@ -157,6 +158,9 @@ Foam::sixDoFRigidBodyMotion::sixDoFRigidBodyMotion
     motionState0_(sDoFRBM.motionState0_),
     restraints_(sDoFRBM.restraints_),
     constraints_(sDoFRBM.constraints_),
+    tConstraints_(sDoFRBM.tConstraints_),
+    rConstraints_(sDoFRBM.rConstraints_),
+    initialCentreOfMass_(sDoFRBM.initialCentreOfMass_),
     initialCentreOfRotation_(sDoFRBM.initialCentreOfRotation_),
     initialQ_(sDoFRBM.initialQ_),
     mass_(sDoFRBM.mass_),