diff --git a/core/AmAppTimer.cpp b/core/AmAppTimer.cpp
index 37fd9789..0abb7b04 100644
--- a/core/AmAppTimer.cpp
+++ b/core/AmAppTimer.cpp
@@ -69,7 +69,7 @@ public:
 };
 
 _AmAppTimer::_AmAppTimer()
-  : direct_timers_mut(true)
+  : direct_timers_mut()
 {
 }
 
diff --git a/core/AmAppTimer.h b/core/AmAppTimer.h
index 9b99a88d..78c6d66c 100644
--- a/core/AmAppTimer.h
+++ b/core/AmAppTimer.h
@@ -57,7 +57,7 @@ class _AmAppTimer
   AmMutex user_timers_mut;
   TimerQueues user_timers;
 
-  AmMutex direct_timers_mut;
+  std::recursive_mutex direct_timers_mut;
   DirectTimers direct_timers;
 
   /** creates timer object and inserts it into our container */
diff --git a/core/AmThread.cpp b/core/AmThread.cpp
index faf38fe5..fffb981a 100644
--- a/core/AmThread.cpp
+++ b/core/AmThread.cpp
@@ -33,18 +33,9 @@
 #include <string>
 using std::string;
 
-AmMutex::AmMutex(bool recursive)
+AmMutex::AmMutex()
 {
-  if(recursive) {
-    pthread_mutexattr_t attr;
-
-    pthread_mutexattr_init(&attr);
-    pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
-    pthread_mutex_init(&m, &attr);
-  }
-  else {
-    pthread_mutex_init(&m,NULL);
-  }
+  pthread_mutex_init(&m,NULL);
 }
 
 AmMutex::~AmMutex()
diff --git a/core/AmThread.h b/core/AmThread.h
index 35190144..75448636 100644
--- a/core/AmThread.h
+++ b/core/AmThread.h
@@ -46,7 +46,7 @@ class AmMutex
   pthread_mutex_t m;
 
 public:
-  AmMutex(bool recursive = false);
+  AmMutex();
   ~AmMutex();
   void lock();
   void unlock();
diff --git a/core/sip/async_file.cpp b/core/sip/async_file.cpp
index b4252270..9ce89e13 100644
--- a/core/sip/async_file.cpp
+++ b/core/sip/async_file.cpp
@@ -20,7 +20,7 @@ Possible issue:
 */
 
 async_file::async_file(unsigned int buf_len)
-  : AmMutex(true), fifo_buffer(buf_len),
+  : fifo_buffer(buf_len),
     evbase(NULL),closed(false),error(false),write_thresh(MIN_WRITE_SIZE)
 {
   if (buf_len <= MIN_WRITE_SIZE) {
@@ -41,7 +41,7 @@ async_file::~async_file()
 
 int async_file::write(const void* buf, unsigned int len)
 {
-  lock_guard<AmMutex> _l(*this);
+  lock_guard<std::recursive_mutex> _l(*this);
   if(closed) return Closed;
   if(error)  return Error;
 
@@ -58,7 +58,7 @@ int async_file::write(const void* buf, unsigned int len)
 
 int async_file::writev(const struct iovec *iov, int iovcnt)
 {
-  lock_guard<AmMutex> _l(*this);
+  lock_guard<std::recursive_mutex> _l(*this);
   if(closed) return Closed;
   if(error)  return Error;
 
@@ -75,7 +75,7 @@ int async_file::writev(const struct iovec *iov, int iovcnt)
 
 void async_file::close()
 {
-  lock_guard<AmMutex> _l(*this);
+  lock_guard<std::recursive_mutex> _l(*this);
   closed = true;
   event_active(ev_write, 0, 0);
 }
@@ -120,6 +120,6 @@ void async_file::write_cycle()
 
 unsigned int async_file::get_buffered_bytes()
 {
-  lock_guard<AmMutex> _l(*this);
+  lock_guard<std::recursive_mutex> _l(*this);
   return fifo_buffer::get_buffered_bytes();
 }
diff --git a/core/sip/async_file.h b/core/sip/async_file.h
index 86312fb5..c2ba35cf 100644
--- a/core/sip/async_file.h
+++ b/core/sip/async_file.h
@@ -6,7 +6,7 @@
 
 class async_file
   : protected fifo_buffer,
-    public AmMutex
+    public std::recursive_mutex
 {
   struct event_base* evbase;
   struct event*    ev_write;