diff --git a/include/boost/fiber/condition.hpp b/include/boost/fiber/condition.hpp
index 3af513d5..180a1765 100644
--- a/include/boost/fiber/condition.hpp
+++ b/include/boost/fiber/condition.hpp
@@ -132,9 +132,12 @@ public:
         catch (...)
         {
             unique_lock< detail::spinlock > lk( splk_);
-            // remove fiber from waiting-list
-            waiting_.erase(
-                    std::find( waiting_.begin(), waiting_.end(), n) );
+            std::deque< detail::fiber_base * >::iterator wit = std::find( waiting_.begin(), waiting_.end(), n);
+            if (wit != waiting_.end())
+            {
+                // remove fiber from waiting-list
+                waiting_.erase( wit );
+            }
             throw;
         }
     }
@@ -169,9 +172,12 @@ public:
                     // this fiber was not notified before timeout
                     // lock spinlock again
                     unique_lock< detail::spinlock > lk( splk_);
-                    // remove fiber from waiting-list
-                    waiting_.erase(
-                        std::find( waiting_.begin(), waiting_.end(), n) );
+                    std::deque< detail::fiber_base * >::iterator wit = std::find( waiting_.begin(), waiting_.end(), n);
+                    if (wit != waiting_.end())
+                    {
+                        // remove fiber from waiting-list
+                        waiting_.erase( wit );
+                    }
 
                     status = cv_status::timeout;
                 }
@@ -209,12 +215,14 @@ public:
                         // timeout happend before notified
                         // lock spinlock
                         unique_lock< detail::spinlock > lk( splk_);
-                        // remove fiber from waiting-list
-                        waiting_.erase(
-                                std::find( waiting_.begin(), waiting_.end(), n) );
+                        std::deque< detail::fiber_base * >::iterator wit = std::find( waiting_.begin(), waiting_.end(), n);
+                        if (wit != waiting_.end())
+                        {
+                            // remove fiber from waiting-list
+                            waiting_.erase(wit);
+                        }
 
                         status = cv_status::timeout;
-
                         break;
                     }
                     // run scheduler
@@ -228,9 +236,12 @@ public:
         catch (...)
         {
             unique_lock< detail::spinlock > lk( splk_);
-            // remove fiber from waiting-list
-            waiting_.erase(
-                std::find( waiting_.begin(), waiting_.end(), n) );
+            std::deque< detail::fiber_base * >::iterator wit = std::find( waiting_.begin(), waiting_.end(), n);
+            if (wit != waiting_.end())
+            {
+                // remove fiber from waiting-list
+                waiting_.erase( wit );
+            }
             throw;
         }
 
diff --git a/src/recursive_timed_mutex.cpp b/src/recursive_timed_mutex.cpp
index cdc8f78a..9ff6e868 100644
--- a/src/recursive_timed_mutex.cpp
+++ b/src/recursive_timed_mutex.cpp
@@ -136,9 +136,12 @@ recursive_timed_mutex::try_lock_until( chrono::high_resolution_clock::time_point
             if ( ! fm_wait_until( timeout_time, lk) )
             {
                 lk.lock();
-                // remove fiber from waiting-list
-                waiting_.erase(
-                    std::find( waiting_.begin(), waiting_.end(), n) );
+                std::deque< detail::fiber_base * >::iterator wit = std::find( waiting_.begin(), waiting_.end(), n);
+                if (wit != waiting_.end())
+                {
+                    // remove fiber from waiting-list
+                    waiting_.erase( wit );
+                }
                 lk.unlock();
                 return false;
             }
@@ -170,9 +173,12 @@ recursive_timed_mutex::try_lock_until( chrono::high_resolution_clock::time_point
                 if ( chrono::high_resolution_clock::now() > timeout_time)
                 {
                     lk.lock();
-                    // remove fiber from waiting-list
-                    waiting_.erase(
-                            std::find( waiting_.begin(), waiting_.end(), n) );
+                    std::deque< detail::fiber_base * >::iterator wit = std::find( waiting_.begin(), waiting_.end(), n);
+                    if (wit != waiting_.end())
+                    {
+                        // remove fiber from waiting-list
+                        waiting_.erase( wit );
+                    }
                     lk.unlock();
                     return false;
                 }
diff --git a/src/timed_mutex.cpp b/src/timed_mutex.cpp
index 51eea444..21d651a9 100644
--- a/src/timed_mutex.cpp
+++ b/src/timed_mutex.cpp
@@ -125,9 +125,12 @@ timed_mutex::try_lock_until( chrono::high_resolution_clock::time_point const& ti
             if ( ! fm_wait_until( timeout_time, lk) )
             {
                 lk.lock();
-                // remove fiber from waiting-list
-                waiting_.erase(
-                    std::find( waiting_.begin(), waiting_.end(), n) );
+                std::deque< detail::fiber_base * >::iterator wit = std::find( waiting_.begin(), waiting_.end(), n);
+                if (wit != waiting_.end())
+                {
+                    // remove fiber from waiting-list
+                    waiting_.erase( wit );
+                }
                 lk.unlock();
                 return false;
             }
@@ -159,9 +162,12 @@ timed_mutex::try_lock_until( chrono::high_resolution_clock::time_point const& ti
                 if ( chrono::high_resolution_clock::now() > timeout_time)
                 {
                     lk.lock();
-                    // remove fiber from waiting-list
-                    waiting_.erase(
-                            std::find( waiting_.begin(), waiting_.end(), n) );
+                    std::deque< detail::fiber_base * >::iterator wit = std::find( waiting_.begin(), waiting_.end(), n);
+                    if (wit != waiting_.end())
+                    {
+                        // remove fiber from waiting-list
+                        waiting_.erase( wit );
+                    }
                     lk.unlock();
                     return false;
                 }