--- ./ckucmd.c.orig	2019-09-11 12:36:53.268603997 -0700
+++ ./ckucmd.c	2019-09-11 12:54:44.334194091 -0700
@@ -7103,7 +7103,7 @@
 
 /* Here we must look inside the stdin buffer - highly platform dependent */
 
-#ifdef _IO_file_flags			/* Linux */
+#ifdef __FILE_defined			/* Linux */
     x = (int) ((stdin->_IO_read_end) - (stdin->_IO_read_ptr));
     debug(F101,"cmdconchk _IO_file_flags","",x);
 #else  /* _IO_file_flags */