diff --git a/src/backend/storage/lmgr/spin.c b/src/backend/storage/lmgr/spin.c
index 9b71744cc6c..e5a9d353730 100644
--- a/src/backend/storage/lmgr/spin.c
+++ b/src/backend/storage/lmgr/spin.c
@@ -30,7 +30,9 @@
 #include "storage/spin.h"
 
 
+#ifndef HAVE_SPINLOCKS
 PGSemaphore SpinlockSemaArray;
+#endif
 
 /*
  * Report the amount of shared memory needed to store semaphores for spinlock