diff --git a/rtc_base/synchronization/mutex_benchmark.cc b/rtc_base/synchronization/mutex_benchmark.cc
index 40adca65d8..ae0e3c38e7 100644
--- a/rtc_base/synchronization/mutex_benchmark.cc
+++ b/rtc_base/synchronization/mutex_benchmark.cc
@@ -38,7 +38,8 @@ void BM_LockWithMutex(benchmark::State& state) {
   static PerfTestData test_data;
   for (auto s : state) {
     RTC_UNUSED(s);
-    benchmark::DoNotOptimize(test_data.AddToCounter(2));
+    int add_to_counter = test_data.AddToCounter(2);
+    benchmark::DoNotOptimize(add_to_counter);
   }
 }