-static SecTransformActionBlock default_can_run = ^{ return (CFTypeRef)NULL; };
-static SecTransformActionBlock default_execute_starting = default_can_run;
-static SecTransformActionBlock default_finalize = default_execute_starting;
-static SecTransformActionBlock default_externalize_data = default_finalize;
+static const SecTransformActionBlock default_can_run = ^{ return (CFTypeRef)NULL; };
+static const SecTransformActionBlock default_execute_starting = default_can_run;
+static const SecTransformActionBlock default_finalize = default_execute_starting;
+static const SecTransformActionBlock default_externalize_data = default_finalize;