diff --git a/libsrc/core/taskmanager.cpp b/libsrc/core/taskmanager.cpp
index b54264f1..b4f96065 100644
--- a/libsrc/core/taskmanager.cpp
+++ b/libsrc/core/taskmanager.cpp
@@ -278,8 +278,7 @@ namespace ngcore
       taskqueue.enqueue (ptoken, { afunc, i, num, endcnt });
   }
 
-  mutex m;
-  bool ProcessTask()
+  bool TaskManager :: ProcessTask()
   {
     TNestedTask task;
     TCToken ctoken(taskqueue); 
diff --git a/libsrc/core/taskmanager.hpp b/libsrc/core/taskmanager.hpp
index 4e057013..af2ae0c7 100644
--- a/libsrc/core/taskmanager.hpp
+++ b/libsrc/core/taskmanager.hpp
@@ -103,6 +103,8 @@ namespace ngcore
 
     static void SetPajeTrace (bool use)  { use_paje_trace = use; }
     
+    NGCORE_API static bool ProcessTask();
+
     NGCORE_API static void CreateJob (const function<void(TaskInfo&)> & afunc, 
                     int antasks = task_manager->GetNumThreads());