diff --git a/libappfuse/FuseBridgeLoop.cc b/libappfuse/FuseBridgeLoop.cc
index f71d0c3..22f381c 100644
--- a/libappfuse/FuseBridgeLoop.cc
+++ b/libappfuse/FuseBridgeLoop.cc
@@ -311,6 +311,8 @@
     }
 };
 
+std::recursive_mutex FuseBridgeLoop::mutex_;
+
 FuseBridgeLoop::FuseBridgeLoop() : opened_(true) {
     base::unique_fd epoll_fd(epoll_create1(EPOLL_CLOEXEC));
     if (epoll_fd.get() == -1) {
@@ -328,7 +330,7 @@
 
     std::unique_ptr<FuseBridgeEntry> bridge(
         new FuseBridgeEntry(mount_id, std::move(dev_fd), std::move(proxy_fd)));
-    std::lock_guard<std::mutex> lock(mutex_);
+    std::lock_guard<std::recursive_mutex> lock(mutex_);
     if (!opened_) {
         LOG(ERROR) << "Tried to add a mount to a closed bridge";
         return false;
@@ -372,7 +374,7 @@
         const bool wait_result = epoll_controller_->Wait(bridges_.size(), &entries);
         LOG(VERBOSE) << "Receive epoll events";
         {
-            std::lock_guard<std::mutex> lock(mutex_);
+            std::lock_guard<std::recursive_mutex> lock(mutex_);
             if (!(wait_result && ProcessEventLocked(entries, callback))) {
                 for (auto it = bridges_.begin(); it != bridges_.end();) {
                     callback->OnClosed(it->second->mount_id());
@@ -385,5 +387,13 @@
     }
 }
 
+void FuseBridgeLoop::Lock() {
+    mutex_.lock();
+}
+
+void FuseBridgeLoop::Unlock() {
+    mutex_.unlock();
+}
+
 }  // namespace fuse
 }  // namespace android
diff --git a/libappfuse/include/libappfuse/FuseBridgeLoop.h b/libappfuse/include/libappfuse/FuseBridgeLoop.h
index 6bfda98..d5fc28f 100644
--- a/libappfuse/include/libappfuse/FuseBridgeLoop.h
+++ b/libappfuse/include/libappfuse/FuseBridgeLoop.h
@@ -50,6 +50,10 @@
     // thread from one which invokes |Start|.
     bool AddBridge(int mount_id, base::unique_fd dev_fd, base::unique_fd proxy_fd);
 
+    static void Lock();
+
+    static void Unlock();
+
   private:
     bool ProcessEventLocked(const std::unordered_set<FuseBridgeEntry*>& entries,
                             FuseBridgeLoopCallback* callback);
@@ -60,7 +64,7 @@
     std::map<int, std::unique_ptr<FuseBridgeEntry>> bridges_;
 
     // Lock for multi-threading.
-    std::mutex mutex_;
+    static std::recursive_mutex mutex_;
 
     bool opened_;