diff --git a/src/google/protobuf/arena.h b/src/google/protobuf/arena.h
index 59e02e0963d2..06e196fbb721 100644
--- a/src/google/protobuf/arena.h
+++ b/src/google/protobuf/arena.h
@@ -438,6 +438,7 @@ class PROTOBUF_EXPORT PROTOBUF_ALIGNAS(8) Arena final {
 
     template <typename U>
     static Arena* GetOwningArena(Rank1, const U* p) {
+      (void) p;
       return nullptr;
     }
 
@@ -468,6 +469,7 @@ class PROTOBUF_EXPORT PROTOBUF_ALIGNAS(8) Arena final {
 
     template <typename U>
     static Arena* GetArenaForAllocation(Rank2, const U* p) {
+      (void) p;
       return nullptr;
     }