diff --git a/Src/Base/AMReX_MultiFab.H b/Src/Base/AMReX_MultiFab.H
index 6cb4c46e7df..8ec62700cc1 100644
--- a/Src/Base/AMReX_MultiFab.H
+++ b/Src/Base/AMReX_MultiFab.H
@@ -492,7 +492,7 @@ public:
      * This uses the same arena and factory in the copy and copies
      * all data.
      */
-    MultiFab deepCopy ();
+    [[nodiscard]] MultiFab deepCopy () const;
 
     /**
     * \brief Copy from src to dst including nghost ghost cells.
diff --git a/Src/Base/AMReX_MultiFab.cpp b/Src/Base/AMReX_MultiFab.cpp
index 41ec0093b62..2a80123836b 100644
--- a/Src/Base/AMReX_MultiFab.cpp
+++ b/Src/Base/AMReX_MultiFab.cpp
@@ -168,9 +168,9 @@ MultiFab::Add (MultiFab& dst, const MultiFab& src,
 }
 
 MultiFab
-MultiFab::deepCopy ()
+MultiFab::deepCopy () const
 {
-    auto mf = MultiFab(
+    MultiFab mf(
         this->boxArray(),
         this->DistributionMap(),
         this->nComp(),