diff --git a/src/google/protobuf/compiler/cpp/message.cc b/src/google/protobuf/compiler/cpp/message.cc
index d5a7de27d06bf..4f2d677480453 100644
--- a/src/google/protobuf/compiler/cpp/message.cc
+++ b/src/google/protobuf/compiler/cpp/message.cc
@@ -4046,7 +4046,7 @@ void MessageGenerator::GenerateClassData(io::Printer* p) {
                 constexpr auto arena_bits = $pbi$::EncodePlacementArenaOffsets({
                     $arena_offsets$,
                 });
-                if (arena_bits.has_value()) {
+                if constexpr (arena_bits.has_value()) {
                   return $pbi$::MessageCreator::$copy_type$(
                       sizeof($classname$), alignof($classname$), *arena_bits);
                 } else {