--- configure.ac.orig	2017-02-18 08:35:06.000000000 -0800
+++ configure.ac	2017-02-18 08:35:26.000000000 -0800
@@ -1152,8 +1152,9 @@
 #   asinh, acosh, atanh, trunc - C99 standard, generally not available on
 #                                older systems
 #   sincos - GLIBC extension
+#   __sincos - APPLE extension
 #
-AC_CHECK_FUNCS(asinh acosh atanh copysign finite sincos trunc)
+AC_CHECK_FUNCS(asinh acosh atanh copysign finite sincos __sincos trunc)
 
 # C99 specifies isinf and isnan as macros.
 # HP-UX provides only macros, no functions.
--- libguile/numbers.c.patch.labs	2017-02-18 08:31:21.000000000 -0800
+++ libguile/numbers.c	2017-02-18 08:34:18.000000000 -0800
@@ -9109,6 +9109,8 @@
      details.  */
 #if (defined HAVE_SINCOS) && (defined __GLIBC__) && (defined _GNU_SOURCE)
   sincos (ang, &s, &c);
+#elif (defined HAVE___SINCOS)
+  __sincos (ang, &s, &c);
 #else
   s = sin (ang);
   c = cos (ang);