diff --git a/src/platform-freebsd.cc b/src/platform-freebsd.cc
index 4a6845ef39..511759c485 100644
--- a/src/platform-freebsd.cc
+++ b/src/platform-freebsd.cc
@@ -554,6 +554,7 @@ class FreeBSDMutex : public Mutex {
     ASSERT(result == 0);
     result = pthread_mutex_init(&mutex_, &attrs);
     ASSERT(result == 0);
+    USE(result);
   }
 
   virtual ~FreeBSDMutex() { pthread_mutex_destroy(&mutex_); }