diff --git a/src/include/storage/shmem.h b/src/include/storage/shmem.h
index 0b7da77ccd..5d86b49e12 100644
--- a/src/include/storage/shmem.h
+++ b/src/include/storage/shmem.h
@@ -50,7 +50,7 @@ extern void RequestAddinShmemSpace(Size size);
  /* max size of data structure string name */
 #define SHMEM_INDEX_KEYSIZE		 (48)
  /* estimated size of the shmem index table (not a hard limit) */
-#define SHMEM_INDEX_SIZE		 (32)
+#define SHMEM_INDEX_SIZE		 (64)
 
 /* this is a hash bucket in the shmem index table */
 typedef struct