--- a/m4/fcntl_h.m4
+++ b/m4/fcntl_h.m4
@@ -8,6 +8,7 @@
 
 AC_DEFUN([gl_FCNTL_H],
 [
+  AC_REQUIRE([gl_FCNTL_H_DEFAULTS])
   AC_CACHE_CHECK([for working fcntl.h], gl_cv_header_working_fcntl_h,
     [AC_RUN_IFELSE(
        [AC_LANG_PROGRAM(
@@ -77,3 +78,17 @@
   FCNTL_H='fcntl.h'
   AC_SUBST([FCNTL_H])
 ])
+
+AC_DEFUN([gl_FCNTL_MODULE_INDICATOR],
+[
+  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
+  AC_REQUIRE([gl_FCNTL_H_DEFAULTS])
+  GNULIB_[]m4_translit([$1],[abcdefghijklmnopqrstuvwxyz./-],[ABCDEFGHIJKLMNOPQRSTUVWXYZ___])=1
+])
+
+AC_DEFUN([gl_FCNTL_H_DEFAULTS],
+[
+  GNULIB_OPEN=0;  AC_SUBST([GNULIB_OPEN])
+  dnl Assume proper GNU behavior unless another module says otherwise.
+  REPLACE_OPEN=0; AC_SUBST([REPLACE_OPEN])
+])