diff --git a/file/prefetch_test.cc b/file/prefetch_test.cc
index de896a99e..fa3c2138d 100644
--- a/file/prefetch_test.cc
+++ b/file/prefetch_test.cc
@@ -168,7 +168,7 @@ TEST_P(PrefetchTest, Basic) {
   // count the keys
   {
     auto iter = std::unique_ptr<Iterator>(db_->NewIterator(ReadOptions()));
-    int num_keys = 0;
+    [[maybe_unused]] int num_keys = 0;
     for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
       num_keys++;
     }
diff --git a/memtable/inlineskiplist_test.cc b/memtable/inlineskiplist_test.cc
index 4523aa770..2261136fa 100644
--- a/memtable/inlineskiplist_test.cc
+++ b/memtable/inlineskiplist_test.cc
@@ -570,7 +570,7 @@ class TestState {
 static void ConcurrentReader(void* arg) {
   TestState* state = reinterpret_cast<TestState*>(arg);
   Random rnd(state->seed_);
-  int64_t reads = 0;
+  [[maybe_unused]] int64_t reads = 0;
   state->Change(TestState::RUNNING);
   while (!state->quit_flag_.load(std::memory_order_acquire)) {
     state->t_.ReadStep(&rnd);
diff --git a/memtable/skiplist_test.cc b/memtable/skiplist_test.cc
index d35bc856d..b74e26cb2 100644
--- a/memtable/skiplist_test.cc
+++ b/memtable/skiplist_test.cc
@@ -344,7 +344,7 @@ class TestState {
 static void ConcurrentReader(void* arg) {
   TestState* state = reinterpret_cast<TestState*>(arg);
   Random rnd(state->seed_);
-  int64_t reads = 0;
+  [[maybe_unused]] int64_t reads = 0;
   state->Change(TestState::RUNNING);
   while (!state->quit_flag_.load(std::memory_order_acquire)) {
     state->t_.ReadStep(&rnd);