diff --git a/Source/hydro/Castro_ctu_hydro.cpp b/Source/hydro/Castro_ctu_hydro.cpp
index b81b6474b2..a9ec18f5d7 100644
--- a/Source/hydro/Castro_ctu_hydro.cpp
+++ b/Source/hydro/Castro_ctu_hydro.cpp
@@ -168,7 +168,10 @@ Castro::construct_ctu_hydro_source(Real time, Real dt)
     }
 
 #ifdef RADIATION
-    FArrayBox rad_flux(The_Async_Arena())[AMREX_SPACEDIM];
+    Vector<FArrayBox> rad_flux;
+    for (int n = 0; n < AMREX_SPACEDIM; ++n) {
+        radflux.push_back(FArrayBox(The_Async_Arena()));
+    }
 #endif
 #if AMREX_SPACEDIM <= 2
     FArrayBox pradial(The_Async_Arena());