diff --git a/Z4co/schedule.ccl b/Z4co/schedule.ccl
index 5398334e..ac259090 100644
--- a/Z4co/schedule.ccl
+++ b/Z4co/schedule.ccl
@@ -68,6 +68,51 @@ if(use_subcycling_wip) {
   STORAGE: Theta_k4
   STORAGE: alphaG_k4
   STORAGE: betaG_k4
+
+  SCHEDULE Z4co_SyncKsOld IN ODESolvers_SyncKsOld
+  {
+    LANG: C
+    SYNC: chi_old
+    SYNC: gamma_tilde_old
+    SYNC: K_hat_old
+    SYNC: A_tilde_old
+    SYNC: Gam_tilde_old
+    SYNC: Theta_old
+    SYNC: alphaG_old
+    SYNC: betaG_old
+    SYNC: chi_k1
+    SYNC: gamma_tilde_k1
+    SYNC: K_hat_k1
+    SYNC: A_tilde_k1
+    SYNC: Gam_tilde_k1
+    SYNC: Theta_k1
+    SYNC: alphaG_k1
+    SYNC: betaG_k1
+    SYNC: chi_k2
+    SYNC: gamma_tilde_k2
+    SYNC: K_hat_k2
+    SYNC: A_tilde_k2
+    SYNC: Gam_tilde_k2
+    SYNC: Theta_k2
+    SYNC: alphaG_k2
+    SYNC: betaG_k2
+    SYNC: chi_k3
+    SYNC: gamma_tilde_k3
+    SYNC: K_hat_k3
+    SYNC: A_tilde_k3
+    SYNC: Gam_tilde_k3
+    SYNC: Theta_k3
+    SYNC: alphaG_k3
+    SYNC: betaG_k3
+    SYNC: chi_k4
+    SYNC: gamma_tilde_k4
+    SYNC: K_hat_k4
+    SYNC: A_tilde_k4
+    SYNC: Gam_tilde_k4
+    SYNC: Theta_k4
+    SYNC: alphaG_k4
+    SYNC: betaG_k4
+  } "Sync old and ks"
 }
 
 
diff --git a/Z4co/src/rhs.cxx b/Z4co/src/rhs.cxx
index 2386abe8..8b084456 100644
--- a/Z4co/src/rhs.cxx
+++ b/Z4co/src/rhs.cxx
@@ -37,6 +37,10 @@ CCTK_DEVICE CCTK_HOST CCTK_ATTRIBUTE_ALWAYS_INLINE inline T Power(T x, int y) {
   return (y == 2) ? Arith::pow2(x) : Arith::pown(x, y);
 }
 
+extern "C" void Z4co_SyncKsOld(CCTK_ARGUMENTS) {
+  // do nothing
+}
+
 extern "C" void Z4co_RHS(CCTK_ARGUMENTS) {
   DECLARE_CCTK_ARGUMENTS_Z4co_RHS;
   DECLARE_CCTK_PARAMETERS;