diff --git a/test/Jamfile b/test/Jamfile
index 4daede5..1dde2c0 100644
--- a/test/Jamfile
+++ b/test/Jamfile
@@ -381,3 +381,19 @@ run ip_hash_test2.cpp ;
 run sp_hash_test4.cpp ;
 run lsp_hash_test.cpp ;
 run lsp_hash_test2.cpp ;
+
+run atomic_count_mt_test.cpp
+  : : : <threading>multi ;
+
+run spinlock_mt_test.cpp
+  : : : <threading>multi ;
+
+run spinlock_pool_mt_test.cpp
+  : : : <threading>multi ;
+
+run shared_ptr_mt_test.cpp
+  : : : <threading>multi ;
+
+run weak_ptr_mt_test.cpp
+  : : : <threading>multi ;
+
diff --git a/test/atomic_count_mt_test.cpp b/test/atomic_count_mt_test.cpp
new file mode 100644
index 0000000..6318e29
--- /dev/null
+++ b/test/atomic_count_mt_test.cpp
@@ -0,0 +1,40 @@
+// Copyright 2018, 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt)
+
+#include <boost/smart_ptr/detail/atomic_count.hpp>
+#include <boost/smart_ptr/detail/lightweight_thread.hpp>
+#include <boost/bind/bind.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+static boost::detail::atomic_count count( 0 );
+
+void f( int n )
+{
+    for( int i = 0; i < n; ++i )
+    {
+        ++count;
+    }
+}
+
+int main()
+{
+    int const N = 100000; // iterations
+    int const M = 8;      // threads
+
+    boost::detail::lw_thread_t th[ M ] = {};
+
+    for( int i = 0; i < M; ++i )
+    {
+        boost::detail::lw_thread_create( th[ i ], boost::bind( f, N ) );
+    }
+
+    for( int i = 0; i < M; ++i )
+    {
+        boost::detail::lw_thread_join( th[ i ] );
+    }
+
+    BOOST_TEST_EQ( count, N * M );
+
+    return boost::report_errors();
+}
diff --git a/test/shared_ptr_mt_test.cpp b/test/shared_ptr_mt_test.cpp
new file mode 100644
index 0000000..8b2f433
--- /dev/null
+++ b/test/shared_ptr_mt_test.cpp
@@ -0,0 +1,46 @@
+// Copyright 2018, 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt)
+
+#include <boost/shared_ptr.hpp>
+#include <boost/weak_ptr.hpp>
+#include <boost/smart_ptr/detail/lightweight_thread.hpp>
+#include <boost/bind/bind.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+static boost::shared_ptr<int> sp( new int );
+
+void f( int n )
+{
+    for( int i = 0; i < n; ++i )
+    {
+        boost::shared_ptr<int> p1( sp );
+        boost::weak_ptr<int> p2( p1 );
+    }
+}
+
+int main()
+{
+    int const N = 100000; // iterations
+    int const M = 8;      // threads
+
+    boost::detail::lw_thread_t th[ M ] = {};
+
+    for( int i = 0; i < M; ++i )
+    {
+        boost::detail::lw_thread_create( th[ i ], boost::bind( f, N ) );
+    }
+
+    for( int i = 0; i < M; ++i )
+    {
+        boost::detail::lw_thread_join( th[ i ] );
+    }
+
+    BOOST_TEST_EQ( sp.use_count(), 1 );
+
+    sp.reset();
+
+    BOOST_TEST_EQ( sp.use_count(), 0 );
+
+    return boost::report_errors();
+}
diff --git a/test/spinlock_mt_test.cpp b/test/spinlock_mt_test.cpp
new file mode 100644
index 0000000..ac667aa
--- /dev/null
+++ b/test/spinlock_mt_test.cpp
@@ -0,0 +1,42 @@
+// Copyright 2018, 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt)
+
+#include <boost/smart_ptr/detail/spinlock.hpp>
+#include <boost/smart_ptr/detail/lightweight_thread.hpp>
+#include <boost/bind/bind.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+static int count = 0;
+static boost::detail::spinlock sp = BOOST_DETAIL_SPINLOCK_INIT;
+
+void f( int n )
+{
+    for( int i = 0; i < n; ++i )
+    {
+        boost::detail::spinlock::scoped_lock lock( sp );
+        ++count;
+    }
+}
+
+int main()
+{
+    int const N = 100000; // iterations
+    int const M = 8;      // threads
+
+    boost::detail::lw_thread_t th[ M ] = {};
+
+    for( int i = 0; i < M; ++i )
+    {
+        boost::detail::lw_thread_create( th[ i ], boost::bind( f, N ) );
+    }
+
+    for( int i = 0; i < M; ++i )
+    {
+        boost::detail::lw_thread_join( th[ i ] );
+    }
+
+    BOOST_TEST_EQ( count, N * M );
+
+    return boost::report_errors();
+}
diff --git a/test/spinlock_pool_mt_test.cpp b/test/spinlock_pool_mt_test.cpp
new file mode 100644
index 0000000..d9f13df
--- /dev/null
+++ b/test/spinlock_pool_mt_test.cpp
@@ -0,0 +1,41 @@
+// Copyright 2018, 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt)
+
+#include <boost/smart_ptr/detail/spinlock_pool.hpp>
+#include <boost/smart_ptr/detail/lightweight_thread.hpp>
+#include <boost/bind/bind.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+static int count = 0;
+
+void f( int n )
+{
+    for( int i = 0; i < n; ++i )
+    {
+        boost::detail::spinlock_pool<0>::scoped_lock lock( &count );
+        ++count;
+    }
+}
+
+int main()
+{
+    int const N = 100000; // iterations
+    int const M = 8;      // threads
+
+    boost::detail::lw_thread_t th[ M ] = {};
+
+    for( int i = 0; i < M; ++i )
+    {
+        boost::detail::lw_thread_create( th[ i ], boost::bind( f, N ) );
+    }
+
+    for( int i = 0; i < M; ++i )
+    {
+        boost::detail::lw_thread_join( th[ i ] );
+    }
+
+    BOOST_TEST_EQ( count, N * M );
+
+    return boost::report_errors();
+}
diff --git a/test/weak_ptr_mt_test.cpp b/test/weak_ptr_mt_test.cpp
new file mode 100644
index 0000000..d4a5a37
--- /dev/null
+++ b/test/weak_ptr_mt_test.cpp
@@ -0,0 +1,74 @@
+// Copyright 2018, 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt)
+
+#include <boost/shared_ptr.hpp>
+#include <boost/weak_ptr.hpp>
+#include <boost/smart_ptr/detail/lightweight_thread.hpp>
+#include <boost/bind/bind.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+static boost::shared_ptr<int> sp( new int );
+static boost::weak_ptr<int> wp( sp );
+
+void f1( int n )
+{
+    for( int i = 0; i < n; ++i )
+    {
+        boost::weak_ptr<int> p1( wp );
+
+        BOOST_TEST( !wp.expired() );
+        BOOST_TEST( wp.lock() != 0 );
+    }
+}
+
+void f2( int n )
+{
+    for( int i = 0; i < n; ++i )
+    {
+        boost::weak_ptr<int> p1( wp );
+
+        BOOST_TEST( wp.expired() );
+        BOOST_TEST( wp.lock() == 0 );
+    }
+}
+
+int main()
+{
+    int const N = 100000; // iterations
+    int const M = 8;      // threads
+
+    boost::detail::lw_thread_t th[ M ] = {};
+
+    for( int i = 0; i < M; ++i )
+    {
+        boost::detail::lw_thread_create( th[ i ], boost::bind( f1, N ) );
+    }
+
+    for( int i = 0; i < M; ++i )
+    {
+        boost::detail::lw_thread_join( th[ i ] );
+    }
+
+    BOOST_TEST_EQ( sp.use_count(), 1 );
+    BOOST_TEST_EQ( wp.use_count(), 1 );
+
+    sp.reset();
+
+    BOOST_TEST_EQ( sp.use_count(), 0 );
+    BOOST_TEST_EQ( wp.use_count(), 0 );
+
+    for( int i = 0; i < M; ++i )
+    {
+        boost::detail::lw_thread_create( th[ i ], boost::bind( f2, N ) );
+    }
+
+    for( int i = 0; i < M; ++i )
+    {
+        boost::detail::lw_thread_join( th[ i ] );
+    }
+
+    wp.reset();
+
+    return boost::report_errors();
+}