diff --git a/configure.in b/configure.in
index fdf1a9dbc..6ef482f73 100644
--- a/configure.in
+++ b/configure.in
@@ -864,9 +864,10 @@ AC_CHECK_HEADERS(floatingpoint.h ieeefp.h nan.h)
 # Reasons for testing:
 #   asinh, acosh, atanh, trunc - C99 standard, generally not available on
 #                                older systems
+#   dirfd - mainly BSD derived, not in older systems
 #   sincos - GLIBC extension
 #
-AC_CHECK_FUNCS(asinh acosh atanh copysign finite sincos trunc)
+AC_CHECK_FUNCS(asinh acosh atanh copysign dirfd finite sincos trunc)
 
 # C99 specifies isinf and isnan as macros.
 # HP-UX provides only macros, no functions.