diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 25e8f72872d36a60abcc8eef3d2fa9532987d8f1..892ce5dbccf91aca149908f0a7f7144520036670 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2017-01-17  Eric Botcazou  <ebotcazou@adacore.com>
+
+	PR ada/67205
+	* config/aarch64/aarch64.c (TARGET_CUSTOM_FUNCTION_DESCRIPTORS): Define
+
 2017-01-17  Jakub Jelinek  <jakub@redhat.com>
 
 	PR debug/71669
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 0cf7d12186af3e05ba8742af5a03425f61f51754..67500c86bc7e4f8c4fee052624e9aa37124da893 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -15025,6 +15025,10 @@ aarch64_libgcc_floating_mode_supported_p
 #undef TARGET_OMIT_STRUCT_RETURN_REG
 #define TARGET_OMIT_STRUCT_RETURN_REG true
 
+/* The architecture reserves bits 0 and 1 so use bit 2 for descriptors.  */
+#undef TARGET_CUSTOM_FUNCTION_DESCRIPTORS
+#define TARGET_CUSTOM_FUNCTION_DESCRIPTORS 4
+
 #if CHECKING_P
 #undef TARGET_RUN_TARGET_SELFTESTS
 #define TARGET_RUN_TARGET_SELFTESTS selftest::aarch64_run_selftests