diff --git a/sys/sys/shm.h b/sys/sys/shm.h
--- a/sys/sys/shm.h
+++ b/sys/sys/shm.h
@@ -51,7 +51,7 @@
 
 #define SHM_RDONLY  010000  /* Attach read-only (else read-write) */
 #define SHM_RND     020000  /* Round attach address to SHMLBA */
-#define	SHM_REMAP   030000  /* Unmap before mapping */
+#define	SHM_REMAP   040000  /* Unmap before mapping */
 #define SHMLBA      PAGE_SIZE /* Segment low boundary address multiple */
 
 /* "official" access mode definitions; somewhat braindead since you have