diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b88b821ea2e..42c3c2009cd 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2004-12-02  Stan Shebs  <shebs@apple.com>
+
+	* config/rs6000/rs6000.c (rs6000_override_options): Make 64-bit
+	Darwin default to one-byte bools.
+
 2004-12-02  Richard Henderson  <rth@redhat.com>
 
 	PR 18774
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index da781605f27..807f5535faf 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -1302,6 +1302,8 @@ rs6000_override_options (const char *default_cpu)
   if (DEFAULT_ABI == ABI_DARWIN && TARGET_64BIT)
     {
       rs6000_darwin64_abi = 1;
+      /* Setting to empty string is same as "-mone-byte-bool".  */
+      darwin_one_byte_bool = "";
     }
 
   /* Handle -mabi= options.  */