diff --git a/src/include/storage/barrier.h b/src/include/storage/barrier.h
index bc61de0ff1..2bef2eb6ad 100644
--- a/src/include/storage/barrier.h
+++ b/src/include/storage/barrier.h
@@ -75,7 +75,7 @@ extern slock_t dummy_spinlock;
  * "lock; addl" has worked for longer than "mfence".
  */
 #define pg_memory_barrier()		\
-	__asm__ __volatile__ ("lock; addl $0,0(%%esp)" : : : "memory")
+	__asm__ __volatile__ ("lock; addl $0,0(%%esp)" : : : "memory", "cc")
 #define pg_read_barrier()		pg_compiler_barrier()
 #define pg_write_barrier()		pg_compiler_barrier()
 #elif defined(__x86_64__)		/* 64 bit x86 */
@@ -89,7 +89,7 @@ extern slock_t dummy_spinlock;
  * do those things, a compiler barrier should be enough.
  */
 #define pg_memory_barrier()		\
-	__asm__ __volatile__ ("lock; addl $0,0(%%rsp)" : : : "memory")
+	__asm__ __volatile__ ("lock; addl $0,0(%%rsp)" : : : "memory", "cc")
 #define pg_read_barrier()		pg_compiler_barrier()
 #define pg_write_barrier()		pg_compiler_barrier()
 #elif defined(__ia64__) || defined(__ia64)