diff --git a/shm.h b/shm.h
index 4c8e9506..0bfb3839 100644
--- a/shm.h
+++ b/shm.h
@@ -49,4 +49,5 @@ void shm_purge(struct wl_shm *shm, unsigned long cookie);
 struct terminal;
 static inline unsigned long shm_cookie_grid(const struct terminal *term) { return (unsigned long)((uintptr_t)term + 0); }
 static inline unsigned long shm_cookie_search(const struct terminal *term) { return (unsigned long)((uintptr_t)term + 1); }
-static inline unsigned long shm_cookie_csd(const struct terminal *term, int n) { return (unsigned long)((uintptr_t)term + 2 + (n)); }
+static inline unsigned long shm_cookie_scrollback_indicator(const struct terminal *term) { return (unsigned long)(uintptr_t)term + 2; }
+static inline unsigned long shm_cookie_csd(const struct terminal *term, int n) { return (unsigned long)((uintptr_t)term + 3 + (n)); }