--- a/Modules/Setup
+++ b/Modules/Setup
@@ -182,7 +182,7 @@
 # Modules with some UNIX dependencies
 
 _posixsubprocess _posixsubprocess.c
-_posixshmem -I$(srcdir)/Modules/_multiprocessing _multiprocessing/posixshmem.c # -lrt # _posixshmem
+_posixshmem -I$(srcdir)/Modules/_multiprocessing _multiprocessing/posixshmem.c -lrt # _posixshmem
 fcntl fcntlmodule.c
 #grp grpmodule.c
 #ossaudiodev ossaudiodev.c