diff --git a/src/lib/allocationcluster.hpp b/src/lib/allocationcluster.hpp
index ada15c501..0e1e85fdd 100644
--- a/src/lib/allocationcluster.hpp
+++ b/src/lib/allocationcluster.hpp
@@ -60,7 +60,6 @@
 
 namespace lib {
   using boost::scoped_ptr;
-  using lumiera::Concurrency;
 
   /**
    * A pile of objects sharing common allocation and lifecycle.
diff --git a/src/lib/concurrency.hpp b/src/lib/concurrency.hpp
index 87ebfa45b..e00f1bd5d 100644
--- a/src/lib/concurrency.hpp
+++ b/src/lib/concurrency.hpp
@@ -34,14 +34,14 @@
  */
 
 
-#ifndef LUMIERA_CONCURRENCY_H
-#define LUMIERA_CONCURRENCY_H
+#ifndef LIB_CONCURRENCY_H
+#define LIB_CONCURRENCY_H
 
 #include "include/nobugcfg.h"
 #include "lib/util.hpp"
 
 
-namespace lumiera {
+namespace lib {
       
     /**
      * Facility for monitor object based locking. 
diff --git a/src/lib/singletonpolicies.hpp b/src/lib/singletonpolicies.hpp
index 25c174a58..e00be62b6 100644
--- a/src/lib/singletonpolicies.hpp
+++ b/src/lib/singletonpolicies.hpp
@@ -139,7 +139,7 @@ namespace lumiera
       struct Multithreaded
         {
           typedef volatile S VolatileType;
-          typedef lumiera::Concurrency::Lock<S> Lock;
+          typedef lib::Concurrency::Lock<S> Lock;
         };
       
       
diff --git a/src/lib/visitordispatcher.hpp b/src/lib/visitordispatcher.hpp
index 5598b243c..46db635b0 100644
--- a/src/lib/visitordispatcher.hpp
+++ b/src/lib/visitordispatcher.hpp
@@ -33,10 +33,10 @@
 #include <vector>
 
 
-namespace lumiera
-  {
-  namespace visitor
-    {
+namespace lumiera {
+  namespace visitor {
+  
+    using lib::Concurrency;
 
     template<class TOOL> class Tag;
     
diff --git a/src/proc/assetmanager.cpp b/src/proc/assetmanager.cpp
index 9251ceaab..7c4b6da06 100644
--- a/src/proc/assetmanager.cpp
+++ b/src/proc/assetmanager.cpp
@@ -39,7 +39,7 @@ using boost::bind;
 using util::for_each;
 
 using lumiera::Singleton;
-using lumiera::Concurrency;
+using lib::Concurrency;
 
 
 namespace asset
diff --git a/src/proc/mobject/session/defsregistry.hpp b/src/proc/mobject/session/defsregistry.hpp
index 89054de66..3920ed143 100644
--- a/src/proc/mobject/session/defsregistry.hpp
+++ b/src/proc/mobject/session/defsregistry.hpp
@@ -53,13 +53,12 @@
 #include <boost/lambda/lambda.hpp>
 
 
-namespace mobject
-  {
-  namespace session
-    {
+namespace mobject {
+  namespace session {
+    
     using lumiera::P;
     using lumiera::Query;
-    using lumiera::Concurrency;
+    using lib::Concurrency;
     using std::tr1::weak_ptr;
     
     using std::string;
diff --git a/tests/common/concurrency-locking-test.cpp b/tests/common/concurrency-locking-test.cpp
index c55aac0bf..7729e4dc4 100644
--- a/tests/common/concurrency-locking-test.cpp
+++ b/tests/common/concurrency-locking-test.cpp
@@ -55,6 +55,7 @@ namespace lib {
       
       
       class Victim
+        : Concurrency
         {
           volatile long cnt_[NUM_COUNTERS];
           volatile uint step_;         ///< @note stored as instance variable
@@ -62,7 +63,7 @@ namespace lib {
           void
           pause ()
             {
-              //Lock guard (*this); // note recursive lock
+              Lock<Victim> guard (this); // note recursive lock
               for ( uint i=0, lim=(rand() % MAX_PAUSE); i<lim; ++i);
             }
           
@@ -87,7 +88,7 @@ namespace lib {
           void 
           inc (uint newStep)
             {
-              //Lock guard (*this);
+              Lock<Victim> guard (this);
               step_ = newStep;
               incrementAll();
             }
@@ -95,7 +96,7 @@ namespace lib {
           bool
           belowLimit ()
             {
-              //Lock guard (*this);
+              Lock<Victim> guard (this);
               return cnt_[0] < MAX_SUM;
             }