diff --git a/src/tools/python.jam b/src/tools/python.jam
index 836a6edf6..c3451a76b 100644
--- a/src/tools/python.jam
+++ b/src/tools/python.jam
@@ -258,7 +258,7 @@ rule init-unix ( version ? : root ? : includes ? : libraries ? : condition * )
         
         case OSF :     
         {
-            extra-libs = pthread z ;
+            extra-libs = pthread ;
             extra-libs-conditional = <toolset>gcc:<source>rt ;
         }