diff --git a/gcc/ada/5wsystem.ads b/gcc/ada/5wsystem.ads
index 4f72f04d0a37..2a7496a98437 100644
--- a/gcc/ada/5wsystem.ads
+++ b/gcc/ada/5wsystem.ads
@@ -138,8 +138,8 @@ private
    Support_Long_Shifts       : constant Boolean := True;
    Suppress_Standard_Library : constant Boolean := False;
    Use_Ada_Main_Program_Name : constant Boolean := False;
-   ZCX_By_Default            : constant Boolean := True;
-   GCC_ZCX_Support           : constant Boolean := True;
+   ZCX_By_Default            : constant Boolean := False;
+   GCC_ZCX_Support           : constant Boolean := False;
    Front_End_ZCX_Support     : constant Boolean := False;
 
    --  Obsolete entries, to be removed eventually (bootstrap issues!)
diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog
index d014410ac9f9..1d55f66fa1f3 100644
--- a/gcc/ada/ChangeLog
+++ b/gcc/ada/ChangeLog
@@ -1,3 +1,7 @@
+2003-12-01  Arnaud Charlet  <charlet@act-europe.fr>
+
+	* 5wsystem.ads: Disable zero cost exception, not ready yet.
+
 2003-11-29  Ulrich Weigand  <uweigand@de.ibm.com>
 
 	* Make-lang.in (nmake.ads): Add dependency on ada/nmake.adb