diff --git a/runtime/atomic.cc b/runtime/atomic.cc
index 63f2cf8..e766a8d 100644
--- a/runtime/atomic.cc
+++ b/runtime/atomic.cc
@@ -31,7 +31,7 @@
   if (kNeedSwapMutexes) {
     gSwapMutexes = new std::vector<Mutex*>;
     for (size_t i = 0; i < kSwapMutexCount; ++i) {
-      gSwapMutexes->push_back(new Mutex("QuasiAtomic stripe"));
+      gSwapMutexes->push_back(new Mutex("QuasiAtomic stripe", kSwapMutexesLock));
     }
   }
 }
diff --git a/runtime/base/mutex.h b/runtime/base/mutex.h
index 1ba6180..81e62ab 100644
--- a/runtime/base/mutex.h
+++ b/runtime/base/mutex.h
@@ -55,6 +55,7 @@
 enum LockLevel {
   kLoggingLock = 0,
   kMemMapsLock,
+  kSwapMutexesLock,
   kUnexpectedSignalLock,
   kThreadSuspendCountLock,
   kAbortLock,