diff --git a/src/common/option.cpp b/src/common/option.cpp
index 2be4a8d46..3a14497d0 100644
--- a/src/common/option.cpp
+++ b/src/common/option.cpp
@@ -21,10 +21,9 @@
 * *****************************************************/
 
 
-#include "common/option.hpp"
-
 #include "lib/error.hpp"
 #include "lib/util.hpp"
+#include "common/option.hpp"
 
 
 
diff --git a/src/gui/gtk-base.hpp b/src/gui/gtk-base.hpp
index e02e9597d..3f0dfd9f5 100644
--- a/src/gui/gtk-base.hpp
+++ b/src/gui/gtk-base.hpp
@@ -40,6 +40,7 @@
 #define GUI_GTK_BASE_H
 
 //--------------------tricky special Include sequence
+#include "lib/hash-standard.hpp"
 #include <locale>
 #include <gtkmm.h>
 #include <nobug.h>
diff --git a/src/gui/guistart.cpp b/src/gui/guistart.cpp
index 6cbd86eef..5aa36ee2a 100644
--- a/src/gui/guistart.cpp
+++ b/src/gui/guistart.cpp
@@ -45,9 +45,12 @@
  ** @see gui::GtkLumiera#main the GTK GUI main
  */
 
+//--------------------tricky special Include sequence
+#include "lib/hash-standard.hpp"// need to be before any inclusion of <string>
 #include <locale>               // need to include this to prevent errors when libintl.h defines textdomain (because gtk-lumiera removes the def when ENABLE_NLS isn't defined)
 
 #include "gui/gtk-lumiera.hpp"  // need to include this before nobugcfg.h, because types.h from GTK tries to shaddow the ERROR macro from windows, which kills nobug's ERROR macro
+//--------------------tricky special Include sequence
 
 #include "lib/error.hpp"
 #include "gui/guifacade.hpp"
diff --git a/src/lib/allocation-cluster.hpp b/src/lib/allocation-cluster.hpp
index 92b72eae0..ab013ecfa 100644
--- a/src/lib/allocation-cluster.hpp
+++ b/src/lib/allocation-cluster.hpp
@@ -47,15 +47,15 @@
 #ifndef LIB_ALLOCATION_CLUSTER_H
 #define LIB_ALLOCATION_CLUSTER_H
 
-#include <vector>
-#include <boost/scoped_ptr.hpp>
-#include <boost/noncopyable.hpp>
-
 #include "lib/error.hpp"
 #include "lib/sync-classlock.hpp"
 #include "lib/scoped-holder.hpp"
 #include "lib/scoped-holder-transfer.hpp"
 
+#include <boost/scoped_ptr.hpp>
+#include <boost/noncopyable.hpp>
+#include <vector>
+
 
 
 namespace lib {
diff --git a/src/lib/cmdline.cpp b/src/lib/cmdline.cpp
index 249121e60..bc10e664d 100644
--- a/src/lib/cmdline.cpp
+++ b/src/lib/cmdline.cpp
@@ -22,9 +22,9 @@
 
 
 
-#include "lib/cmdline.hpp"
 #include "lib/util.hpp"
 #include "include/logging.h"
+#include "lib/cmdline.hpp"
 
 #include <boost/regex.hpp>
 #include <boost/algorithm/string/join.hpp>
diff --git a/src/lib/error.hpp b/src/lib/error.hpp
index 14872b710..fa6e6869d 100644
--- a/src/lib/error.hpp
+++ b/src/lib/error.hpp
@@ -39,11 +39,10 @@
 #ifndef LUMIERA_ERROR_HPP_
 #define LUMIERA_ERROR_HPP_
 
-#include <string>
 #include "include/logging.h"
 #include "include/lifecycle.h"
 #include "lib/error.h"
-
+#include <string>
 
 namespace lumiera {
   
diff --git a/src/lib/hash-indexed.hpp b/src/lib/hash-indexed.hpp
index 6c547b31c..7069d296f 100644
--- a/src/lib/hash-indexed.hpp
+++ b/src/lib/hash-indexed.hpp
@@ -209,24 +209,4 @@ namespace lib {
   
   
 } // namespace lib
-
-
-/////////////////////////////////////////////////////////////////////////TICKET #722 : should provide a generic bridge to use hash_value
-
-// The following doesn't work as expected, probably because of sub type relationship not being detected when picking a template specialisation
-// see also hash-standard.hpp
-
-//namespace std {
-//  
-//  template<typename BA, typename IMP>
-//  struct hash<lib::HashIndexed<BA,IMP> >
-//  {
-//    size_t
-//    operator() (lib::HashIndexed<BA,IMP> const& val)  const noexcept
-//      {
-//        return hash_value(val);
-//      }
-//  };
-//  
-//}
 #endif
diff --git a/src/lib/symbol.hpp b/src/lib/symbol.hpp
index 7fb044bbc..3fc613572 100644
--- a/src/lib/symbol.hpp
+++ b/src/lib/symbol.hpp
@@ -41,6 +41,7 @@
 #ifndef LIB_SYMBOL_H
 #define LIB_SYMBOL_H
 
+#include "lib/hash-standard.hpp"
 
 #include <string>
 #include <cstring>
diff --git a/src/lib/test/suite.cpp b/src/lib/test/suite.cpp
index 37c2b0bca..8028eb2f9 100644
--- a/src/lib/test/suite.cpp
+++ b/src/lib/test/suite.cpp
@@ -23,10 +23,11 @@
 
 
 #include "include/logging.h"
-#include "lib/cmdline.hpp"
+#include "lib/hash-standard.hpp"
 #include "lib/test/test-helper.hpp"
 #include "lib/test/suite.hpp"
 #include "lib/test/run.hpp"
+#include "lib/cmdline.hpp"
 #include "lib/error.hpp"
 #include "lib/util.hpp"
 
diff --git a/src/lib/test/testoption.cpp b/src/lib/test/testoption.cpp
index dcb64aedb..99ab9cb77 100644
--- a/src/lib/test/testoption.cpp
+++ b/src/lib/test/testoption.cpp
@@ -21,10 +21,10 @@
 * *****************************************************/
 
 
+#include "lib/error.hpp"
 #include "lib/test/testoption.hpp"
 #include "lib/test/suite.hpp"
 
-#include "lib/error.hpp"
 
 
 
diff --git a/src/lib/util.hpp b/src/lib/util.hpp
index a55ff3aed..6c36c2959 100644
--- a/src/lib/util.hpp
+++ b/src/lib/util.hpp
@@ -25,6 +25,7 @@
 #define LIB_UTIL_H
 
 #include "include/limits.h"
+#include "lib/hash-standard.hpp"
 
 #include <set>
 #include <string>
diff --git a/src/proc/asset/category.hpp b/src/proc/asset/category.hpp
index 32f8a75a3..6180c156b 100644
--- a/src/proc/asset/category.hpp
+++ b/src/proc/asset/category.hpp
@@ -25,6 +25,7 @@
 #define PROC_ASSET_CATEGORY_H
 
 #include "lib/symbol.hpp"
+#include "lib/hash-standard.hpp"
 
 #include <string>
 #include <boost/functional/hash.hpp>
diff --git a/src/proc/mobject/builder/operationpoint.hpp b/src/proc/mobject/builder/operationpoint.hpp
index 981d7a75e..09b54fd81 100644
--- a/src/proc/mobject/builder/operationpoint.hpp
+++ b/src/proc/mobject/builder/operationpoint.hpp
@@ -26,6 +26,7 @@
 
 //#include "proc/engine/procnode.hpp"         /////TODO can we get rid of this header here?
 //#include "common/query.hpp"
+#include "lib/hash-standard.hpp"
 
 #include <boost/scoped_ptr.hpp>
 #include <vector>
diff --git a/src/proc/mobject/session/allocation.hpp b/src/proc/mobject/session/allocation.hpp
index 03f3d302d..5f263310d 100644
--- a/src/proc/mobject/session/allocation.hpp
+++ b/src/proc/mobject/session/allocation.hpp
@@ -24,11 +24,9 @@
 #ifndef PROC_MOBJECT_SESSION_ALLOCATION_H
 #define PROC_MOBJECT_SESSION_ALLOCATION_H
 
-#include <string>
-
 #include "proc/mobject/session/locatingpin.hpp"
 
-
+#include <string>
 using std::string;
 
 
diff --git a/tests/library/test/testoptiontest.cpp b/tests/library/test/testoptiontest.cpp
index 3646148f8..efde8c0ae 100644
--- a/tests/library/test/testoptiontest.cpp
+++ b/tests/library/test/testoptiontest.cpp
@@ -21,11 +21,12 @@
 * *****************************************************/
 
 
-#include <iostream>
 #include "lib/test/run.hpp"
 #include "lib/test/testoption.hpp"
 #include "lib/util.hpp"
 
+#include <iostream>
+
 using lib::Cmdline;
 using util::isnil;
 using std::endl;
diff --git a/tests/testrunner.cpp b/tests/testrunner.cpp
index 28dd91a77..494aebcf6 100644
--- a/tests/testrunner.cpp
+++ b/tests/testrunner.cpp
@@ -21,9 +21,9 @@
 */
 
 
-#include "lib/test/suite.hpp"
-#include "lib/test/testoption.hpp"
 #include "include/lifecycle.h"
+#include "lib/test/testoption.hpp"
+#include "lib/test/suite.hpp"
 
 using lumiera::LifecycleHook;
 using lumiera::ON_GLOBAL_INIT;