diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog
index 6396196a57b7a06d4a777e57513aed6882a67fe8..12fee98eb26b8ac3381e7f0815a41f78af3771ce 100644
--- a/gcc/ada/ChangeLog
+++ b/gcc/ada/ChangeLog
@@ -1,3 +1,8 @@
+2019-07-02  Iain Sandoe  <iain@sandoe.co.uk>
+
+	* libgnat/system-darwin-ppc.ads: Set Stack_Check_Probes True for
+	PPC Darwin.
+
 2019-07-01  Ed Schonberg  <schonberg@adacore.com>
 
 	* sem_ch12.adb (Is_Defaulted): New predicate in
diff --git a/gcc/ada/libgnat/system-darwin-ppc.ads b/gcc/ada/libgnat/system-darwin-ppc.ads
index d314b66595daa149add77b57c8cfd42991dc8b66..9adc2deacdcfd3c69371466563d41558e1c93369 100644
--- a/gcc/ada/libgnat/system-darwin-ppc.ads
+++ b/gcc/ada/libgnat/system-darwin-ppc.ads
@@ -158,7 +158,7 @@ private
    Preallocated_Stacks       : constant Boolean := False;
    Signed_Zeros              : constant Boolean := True;
    Stack_Check_Default       : constant Boolean := False;
-   Stack_Check_Probes        : constant Boolean := False;
+   Stack_Check_Probes        : constant Boolean := True;
    Stack_Check_Limits        : constant Boolean := False;
    Support_Aggregates        : constant Boolean := True;
    Support_Atomic_Primitives : constant Boolean := Word_Size = 64;