diff --git a/libs/thread/build/Jamfile.v2 b/libs/thread/build/Jamfile.v2
index eeed31d..7ac389a 100644
--- a/libs/thread/build/Jamfile.v2
+++ b/libs/thread/build/Jamfile.v2
@@ -37,6 +37,32 @@ import feature ;
 import indirect ;
 import path ;
 
+feature.feature threadapi : pthread win32 : propagated ;
+
+rule set_default_threadapi ( properties * )
+{
+    echo "set props" $(properties) ;
+
+    local api = pthread ;
+    if <target-os>windows in $(properties) { api = win32 ; }
+    if <target-os>linux in $(properties) { api = pthread ; }
+    #if [ os.name ] = "NT" { api = win32 ; }
+
+    return $(api) ;
+}
+
+rule check_default_threadapi ( properties * )
+{
+    echo "check props" $(properties) ;
+
+    local api = pthread ;
+    if <target-os>windows in $(properties) { api = win32 ; }
+    if <target-os>linux in $(properties) { api = pthread ; }
+    #if [ os.name ] = "NT" { api = win32 ; }
+
+    return <threadapi>$(api) ;
+}
+
 project boost/thread
     : source-location ../src
     : requirements <threading>multi
@@ -106,6 +132,7 @@ project boost/thread
         <toolset>intel:<cxxflags>-wd1418
         <toolset>intel:<cxxflags>-wd2415 
 
+        <conditional>@check_default_threadapi
 
     # : default-build <threading>multi
     : usage-requirements  # pass these requirement to dependents (i.e. users)
@@ -118,15 +145,7 @@ project boost/thread
       <library>/boost/system//boost_system
     ;
 
-local rule default_threadapi ( )
-{
-    local api = pthread ;
-    if [ os.name ] = "NT" { api = win32 ; }
-    return $(api) ;
-}
-
-feature.feature threadapi : pthread win32 : propagated ;
-feature.set-default threadapi : [ default_threadapi ] ;
+feature.set-default threadapi : [ set_default_threadapi ] ;
 
 rule tag ( name : type ? : property-set )
 {
@@ -137,7 +156,7 @@ rule tag ( name : type ? : property-set )
         local api = [ $(property-set).get <threadapi> ] ;
 
         # non native api gets additional tag
-        if $(api) != [ default_threadapi ] {
+        if $(api) != [ set_default_threadapi ] {
             result = $(result)_$(api) ;
         }
     }