diff --git a/Source/mhd/Castro_mhd.H b/Source/mhd/Castro_mhd.H
index 3451fefe37..a15a323207 100644
--- a/Source/mhd/Castro_mhd.H
+++ b/Source/mhd/Castro_mhd.H
@@ -31,7 +31,7 @@
 
     void
     consup_mhd(const amrex::Box& bx, const Real dt,
-               amrex::Array4<amrex::Real> const& update,
+               amrex::Array4<amrex::Real> const& U_new,
                amrex::Array4<amrex::Real const> const& flux0,
                amrex::Array4<amrex::Real const> const& flux1,
                amrex::Array4<amrex::Real const> const& flux2);
diff --git a/Source/mhd/mhd_util.H b/Source/mhd/mhd_util.H
index 7b7cce3eba..7f9097e4f5 100644
--- a/Source/mhd/mhd_util.H
+++ b/Source/mhd/mhd_util.H
@@ -23,7 +23,7 @@ eos_soundspeed_mhd(Real& c, Real as, Real ca, Real bd) {
 
 AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
 void
-qflux(Real* qflx, Real* flx, Real* q_zone) {
+qflux(Real* qflx, const Real* flx, const Real* q_zone) {
 
   // Calculate the C to P Jacobian applied to the fluxes
 
@@ -78,7 +78,7 @@ qflux(Real* qflx, Real* flx, Real* q_zone) {
 
 AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
 void
-electric(Real* q_zone, Real& E_zone, const int comp) {
+electric(const Real* q_zone, Real& E_zone, const int comp) {
 
   // this takes the cell-center primitive state, q_zone, and computes the cell-center
   // electric field, E_zone, using Faraday's law:
@@ -99,7 +99,7 @@ electric(Real* q_zone, Real& E_zone, const int comp) {
 
 AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
 void
-ConsToPrim(Real* q_zone, Real* U_zone) {
+ConsToPrim(Real* q_zone, const Real* U_zone) {
 
   // calculate the primitive variables from the conserved
   // U has NUM_STATE+3 components
diff --git a/Source/sources/Castro_sources.cpp b/Source/sources/Castro_sources.cpp
index f99aac52dc..fc5dddce4f 100644
--- a/Source/sources/Castro_sources.cpp
+++ b/Source/sources/Castro_sources.cpp
@@ -606,6 +606,9 @@ Castro::post_advance_operators (Real time, Real dt)
 {
     advance_status status {};
 
+    amrex::ignore_unused(time);
+    amrex::ignore_unused(dt);
+
 #ifndef TRUE_SDC
 #ifdef REACTIONS
     status = do_new_reactions(time, dt);