diff --git a/src/tools/vacpp.jam b/src/tools/vacpp.jam
index c415fc299..5addf28e3 100644
--- a/src/tools/vacpp.jam
+++ b/src/tools/vacpp.jam
@@ -60,7 +60,7 @@ flags vacpp C++FLAGS <rtti>on : -qrtti ;
 # Enable 64-bit memory addressing model
 flags vacpp CFLAGS <address-model>64 : -q64 ;
 flags vacpp LINKFLAGS <address-model>64 : -q64 ;
-flags vacpp ARFLAGS <address-model>64 : -X 64 ;
+flags vacpp ARFLAGS <target-os>aix/<address-model>64 : -X 64 ;
 
 # Use absolute path when generating debug information
 flags vacpp CFLAGS <debug-symbols>on : -g -qfullpath ;