diff --git a/src/converter/builtin_converters.cpp b/src/converter/builtin_converters.cpp
index 9900602b7..b34f633df 100644
--- a/src/converter/builtin_converters.cpp
+++ b/src/converter/builtin_converters.cpp
@@ -30,8 +30,40 @@ shared_ptr_deleter::shared_ptr_deleter(handle<> owner)
 
 shared_ptr_deleter::~shared_ptr_deleter() {}
 
+#if PY_VERSION_HEX >= 0x02040000 && defined(WITH_THREAD)
+namespace
+{
+
+  class scoped_gil_state
+  {
+   public:
+      scoped_gil_state()
+      {
+          if ((m_py_threads_initialized = PyEval_ThreadsInitialized())) {
+              m_gil_state = PyGILState_Ensure();
+          }
+      }
+
+      ~scoped_gil_state()
+      {
+          if (m_py_threads_initialized) {
+              PyGILState_Release(m_gil_state);
+          }
+      }
+
+   private:
+      PyGILState_STATE m_gil_state;
+      bool m_py_threads_initialized;
+  };
+
+}
+#endif
+
 void shared_ptr_deleter::operator()(void const*)
 {
+#if PY_VERSION_HEX >= 0x02040000 && defined(WITH_THREAD)
+    scoped_gil_state gil;
+#endif
     owner.reset();
 }