diff -ur old/once.cpp new/once.cpp
--- old/once.cpp	2011-04-28 12:31:03.000000000 +0200
+++ new/once.cpp	2011-04-28 12:37:23.000000000 +0200
@@ -8,6 +8,7 @@
 #include <boost/assert.hpp>
 #include <pthread.h>
 #include <stdlib.h>
+#include <string.h>
 
 namespace boost
 {
@@ -21,6 +22,7 @@
         {
             pthread_key_t epoch_tss_key;
             pthread_once_t epoch_tss_key_flag=PTHREAD_ONCE_INIT;
+            const pthread_once_t pthread_once_init_value=PTHREAD_ONCE_INIT;
             
             extern "C" void delete_epoch_tss_data(void* data)
             {
@@ -31,7 +33,12 @@
             {
                 BOOST_VERIFY(!pthread_key_create(&epoch_tss_key,delete_epoch_tss_data));
             }
-            
+
+            void __attribute__((destructor)) delete_epoch_tss_key_on_dlclose()
+            {
+                if(memcmp(&epoch_tss_key_flag, &pthread_once_init_value, sizeof(pthread_once_t)))
+                    pthread_key_delete(epoch_tss_key);
+            }
         }
         
         boost::uintmax_t& get_once_per_thread_epoch()
diff -ur old/thread.cpp new/thread.cpp
--- old/thread.cpp	2011-04-28 12:31:09.000000000 +0200
+++ new/thread.cpp	2011-04-28 12:38:21.000000000 +0200
@@ -101,6 +101,12 @@
             {
                 BOOST_VERIFY(!pthread_key_create(&current_thread_tls_key,&tls_destructor));
             }
+			
+            void __attribute__((destructor)) delete_current_thread_tls_key_on_dlclose()
+            {
+                if (current_thread_tls_init_flag.epoch!=BOOST_ONCE_INITIAL_FLAG_VALUE)
+                    pthread_key_delete(current_thread_tls_key);
+            }
         }
         
         boost::detail::thread_data_base* get_current_thread_data()