Index: lib_pypy/_posixshmem_build.py
--- lib_pypy/_posixshmem_build.py.orig
+++ lib_pypy/_posixshmem_build.py
@@ -17,7 +17,7 @@ SOURCE = """
 #include <fcntl.h>           /* For O_* constants */
 """
 
-if sys.platform == 'darwin':
+if sys.platform == 'darwin' or sys.platform.startswith('openbsd'):
     libraries = []
 else:
     libraries=['rt']
