--- a/configure.in
+++ b/configure.in
@@ -16,7 +16,7 @@
   ISO C90 headers unconditionally.])dnl
 # Autoupdate added the next two lines to ensure that your configure
 # script's behavior did not change.  They are probably safe to remove.
-AC_CHECK_INCLUDES_DEFAULT
+# AC_CHECK_INCLUDES_DEFAULT is not supported in debian bullseye
 AC_PROG_EGREP
 
 
