diff --git a/src/vim.h b/src/vim.h
index 5f49c34..abe0b24 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -932,6 +932,7 @@
 #define BLN_DUMMY	4	/* allocating dummy buffer */
 #define BLN_NEW		8	/* create a new buffer */
 #define BLN_NOOPT	16	/* don't copy options to existing buffer */
+#define BLN_DUMMY_OK	32	/* also find an existing dummy buffer */
 
 /* Values for in_cinkeys() */
 #define KEY_OPEN_FORW	0x101
@@ -2402,4 +2403,8 @@
 /* Lowest number used for window ID. Cannot have this many windows. */
 #define LOWEST_WIN_ID 1000
 
+/* Used by the garbage collector. */
+#define COPYID_INC 2
+#define COPYID_MASK (~0x1)
+
 #endif /* VIM__H */