diff --git a/checkin_notes b/checkin_notes
index 82c9d99a06..feff535114 100644
--- a/checkin_notes
+++ b/checkin_notes
@@ -11091,3 +11091,4 @@ Charlie 16 Nov 2007
     mac_build/
         boinc.xcodeproj/
             project.pbxproj
+        BuildMacBOINC.sh
diff --git a/mac_build/BuildMacBOINC.sh b/mac_build/BuildMacBOINC.sh
index e7cfd66694..d5f3ab386a 100644
--- a/mac_build/BuildMacBOINC.sh
+++ b/mac_build/BuildMacBOINC.sh
@@ -56,12 +56,31 @@
 ##
 
 targets=""
-style="Deployment"
 doclean="clean"
 buildall=0
 buildlibs=0
 buildclient=0
 
+DarwinVersion=`uname -r`;
+DarwinMajorVersion=`echo $DarwinVersion | sed 's/\([0-9]*\)[.].*/\1/' `;
+# DarwinMinorVersion=`echo $version | sed 's/[0-9]*[.]\([0-9]*\).*/\1/' `;
+#
+# echo "major = $DarwinMajorVersion"
+# echo "minor = $DarwinMinorVersion"
+#
+# Darwin version 9.x.y corresponds to OS 10.5.x
+# Darwin version 8.x.y corresponds to OS 10.4.x
+# Darwin version 7.x.y corresponds to OS 10.3.x
+# Darwin version 6.x corresponds to OS 10.2.x
+
+if [ "$DarwinMajorVersion" = "9" ]; then
+    # OS 10.5
+    style="Deployment"
+else
+    style="Deployment-no64"
+    fi
+fi
+
 while [ $# -gt 0 ]; do
   case "$1" in 
     -noclean ) doclean="" ; shift 1 ;;