diff --git a/lib/process_shared/posix/semaphore.rb b/lib/process_shared/posix/semaphore.rb
index 1f3c4e0..262c025 100644
--- a/lib/process_shared/posix/semaphore.rb
+++ b/lib/process_shared/posix/semaphore.rb
@@ -46,8 +46,8 @@ module ProcessShared
       # +shm_unlink+ on +sem+.
       #
       # @return [Proc] a finalizer
-      def self.make_finalizer(sem)
-        proc { SharedMemory::Foreign.shm_unlink(sem) }
+      def self.make_finalizer(sem) # already called in SharedMemory
+        Proc.new{}
       end
 
       # Create a new semaphore with initial value +value+.  After