diff --git a/library/dialect/swi/fli/swi.c b/library/dialect/swi/fli/swi.c
index 81a353109..f61433941 100755
--- a/library/dialect/swi/fli/swi.c
+++ b/library/dialect/swi/fli/swi.c
@@ -2508,7 +2508,8 @@ PL_thread_raise(int tid, int sig)
   if ( !REMOTE_ThreadHandle(tid).in_use )
     goto error;
 
-  if ( !raiseSignal(tid, sig) ||
+
+  if ( !raiseSignal(REMOTE_PL_local_data_p(tid), sig) ||
        !alertThread(tid) )
     goto error;
 
@@ -2516,6 +2517,16 @@ PL_thread_raise(int tid, int sig)
 
   return TRUE;
 }
+#else
+
+int
+PL_thread_raise(int tid, int sig)
+{ 
+  if ( !raiseSignal(NULL, sig) )
+    return FALSE;
+
+  return TRUE;
+}
 
 #endif
 
diff --git a/library/system.yap b/library/system.yap
old mode 100644
new mode 100755
index 7dc64248a..5c84c5e30
--- a/library/system.yap
+++ b/library/system.yap
@@ -48,8 +48,10 @@
 
 :- use_module(library(lists), [append/3]).
 
+:- if(current_prolog_flag(windows, false)). 
 :- reexport(library(unix), [wait/2,
 			     kill/2]).
+:- endif.
 
 :- load_foreign_files([sys], [], init_sys).