diff --git a/lib/buildit b/lib/buildit
index 13d6f8e0..0b191f38 100755
--- a/lib/buildit
+++ b/lib/buildit
@@ -26,7 +26,7 @@ if [ -z $MACOSX_DEPLOYMENT_TARGET ]
 then
 	if [ -z $IPHONEOS_DEPLOYMENT_TARGET ]
 	then
-		MACOSX_DEPLOYMENT_TARGET=10.6
+		MACOSX_DEPLOYMENT_TARGET=10.7
 	fi
 fi
 
@@ -75,7 +75,8 @@ case $TRIPLE in
 			-lSystem  \
 			-Wl,-unexported_symbols_list,libc++unexp.exp  \
 			${RE_EXPORT_LINE}  \
-			-Wl,-force_symbols_not_weak_list,notweak.exp "
+			-Wl,-force_symbols_not_weak_list,notweak.exp \
+			-Wl,-force_symbols_weak_list,weak.exp"
 	fi
     ;;
   *-*-mingw*)
diff --git a/lib/weak.exp b/lib/weak.exp
new file mode 100644
index 00000000..6bdcc057
--- /dev/null
+++ b/lib/weak.exp
@@ -0,0 +1,16 @@
+__ZTISt10bad_typeid
+__ZTISt11logic_error
+__ZTISt11range_error
+__ZTISt12domain_error
+__ZTISt12length_error
+__ZTISt12out_of_range
+__ZTISt13bad_exception
+__ZTISt13runtime_error
+__ZTISt14overflow_error
+__ZTISt15underflow_error
+__ZTISt16invalid_argument
+__ZTISt16nested_exception
+__ZTISt20bad_array_new_length
+__ZTISt8bad_cast
+__ZTISt9bad_alloc
+__ZTISt9exception