diff --git a/src/globals.h b/src/globals.h
index 6faee3b..92b2803 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -424,11 +424,18 @@
 
 EXTERN int	modified_was_set;		// did ":set modified"
 EXTERN int	did_filetype INIT(= FALSE);	// FileType event found
-EXTERN int	au_did_filetype INIT(= FALSE);
 EXTERN int	keep_filetype INIT(= FALSE);	// value for did_filetype when
 						// starting to execute
 						// autocommands
 
+// Set by the apply_autocmds_group function if the given event is equal to
+// EVENT_FILETYPE. Used by the readfile function in order to determine if
+// EVENT_BUFREADPOST triggered the EVENT_FILETYPE.
+//
+// Relying on this value requires one to reset it prior calling
+// apply_autocmds_group.
+EXTERN int	au_did_filetype INIT(= FALSE);
+
 // When deleting the current buffer, another one must be loaded.  If we know
 // which one is preferred, au_new_curbuf is set to it
 EXTERN bufref_T	au_new_curbuf INIT(= {NULL COMMA 0 COMMA 0});