diff --git a/RbcUkqcd.hpp b/RbcUkqcd.hpp
index 205b28b..f61002e 100644
--- a/RbcUkqcd.hpp
+++ b/RbcUkqcd.hpp
@@ -214,7 +214,7 @@ void RbcUkqcd::addLightRuntimeLCDSolver(Application &app, const RbcUkqcd::Ensemb
   actionPar.M5 = par.M5;
   actionPar.mass = par.ml;
   actionPar.scale = par.scale;
-  actionPar.boundary = "1 1 1 1";
+  actionPar.boundary = "1 1 1 -1";
   actionPar.twist = "0. 0. 0. 0.";
   app.createModule<MAction::ScaledDWF>(prefix + "_dwf", actionPar);
   actionPar.gauge = prefix + "_gauge_fp32";