diff --git a/src/structs.h b/src/structs.h
index 6cdfb4f..8d86d11 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -2633,6 +2633,8 @@
     int		b_flags;	// various BF_ flags
     int		b_locked;	// Buffer is being closed or referenced, don't
 				// let autocommands wipe it out.
+    int		b_locked_split;	// Buffer is being closed, don't allow opening
+				// a new window with it.
 
     /*
      * b_ffname has the full path of the file (NULL for no name).