diff --git a/treesource.c b/treesource.c
index c09aafa..33eeba5 100644
--- a/treesource.c
+++ b/treesource.c
@@ -23,6 +23,7 @@
 
 extern FILE *yyin;
 extern int yyparse(void);
+extern YYLTYPE yylloc;
 
 struct boot_info *the_boot_info;
 int treesource_error;
@@ -34,6 +35,7 @@ struct boot_info *dt_from_source(const char *fname)
 
 	srcfile_push(fname);
 	yyin = current_srcfile->f;
+	yylloc.file = current_srcfile;
 
 	if (yyparse() != 0)
 		die("Unable to parse input tree\n");