diff --git a/lib/cpp/src/concurrency/Mutex.cpp b/lib/cpp/src/concurrency/Mutex.cpp
index 695d5dc..a055656 100644
--- a/lib/cpp/src/concurrency/Mutex.cpp
+++ b/lib/cpp/src/concurrency/Mutex.cpp
@@ -9,6 +9,8 @@
 #include <assert.h>
 #include <pthread.h>
 
+using boost::shared_ptr;
+
 namespace facebook { namespace thrift { namespace concurrency { 
 
 /** 
diff --git a/lib/cpp/src/concurrency/Mutex.h b/lib/cpp/src/concurrency/Mutex.h
index dd35edb..7594339 100644
--- a/lib/cpp/src/concurrency/Mutex.h
+++ b/lib/cpp/src/concurrency/Mutex.h
@@ -8,7 +8,6 @@
 #define _THRIFT_CONCURRENCY_MUTEX_H_ 1
 
 #include <boost/shared_ptr.hpp>
-using boost::shared_ptr;
 
 namespace facebook { namespace thrift { namespace concurrency { 
 
@@ -29,7 +28,7 @@
  private:
 
   class impl;
-  shared_ptr<impl> impl_;
+  boost::shared_ptr<impl> impl_;
 };
 
 class ReadWriteMutex {
@@ -51,7 +50,7 @@
 private:
 
   class impl;
-  shared_ptr<impl> impl_;
+  boost::shared_ptr<impl> impl_;
 };
 
 class Guard {