diff --git a/Hadrons/Modules/MAction/DWF.hpp b/Hadrons/Modules/MAction/DWF.hpp
index 257782a1..a7104b42 100644
--- a/Hadrons/Modules/MAction/DWF.hpp
+++ b/Hadrons/Modules/MAction/DWF.hpp
@@ -49,7 +49,8 @@ public:
                                     unsigned int, Ls,
                                     double      , mass,
                                     double      , M5,
-                                    std::string , boundary);
+                                    std::string , boundary,
+                                    std::string , twist);
 };
 
 template <typename FImpl>
@@ -119,8 +120,9 @@ void TDWF<FImpl>::setup(void)
     auto &grb4 = *envGetRbGrid(FermionField);
     auto &g5   = *envGetGrid(FermionField, par().Ls);
     auto &grb5 = *envGetRbGrid(FermionField, par().Ls);
-    std::vector<Complex> boundary = strToVec<Complex>(par().boundary);
-    typename DomainWallFermion<FImpl>::ImplParams implParams(boundary);
+    typename DomainWallFermion<FImpl>::ImplParams implParams;
+    implParams.boundary_phases = strToVec<Complex>(par().boundary);
+    implParams.twist_n_2pi_L   = strToVec<Real>(par().twist);
     envCreateDerived(FMat, DomainWallFermion<FImpl>, getName(), par().Ls, U, g5,
                      grb5, g4, grb4, par().mass, par().M5, implParams);
 }
diff --git a/Hadrons/Modules/MAction/MobiusDWF.hpp b/Hadrons/Modules/MAction/MobiusDWF.hpp
index 01223267..0ba9c4c3 100644
--- a/Hadrons/Modules/MAction/MobiusDWF.hpp
+++ b/Hadrons/Modules/MAction/MobiusDWF.hpp
@@ -49,7 +49,8 @@ public:
                                     double      , M5,
                                     double      , b,
                                     double      , c,
-                                    std::string , boundary);
+                                    std::string , boundary,
+                                    std::string , twist);
 };
 
 template <typename FImpl>
@@ -119,8 +120,9 @@ void TMobiusDWF<FImpl>::setup(void)
     auto &grb4 = *envGetRbGrid(FermionField);
     auto &g5   = *envGetGrid(FermionField, par().Ls);
     auto &grb5 = *envGetRbGrid(FermionField, par().Ls);
-    std::vector<Complex> boundary = strToVec<Complex>(par().boundary);
-    typename MobiusFermion<FImpl>::ImplParams implParams(boundary);
+    typename MobiusFermion<FImpl>::ImplParams implParams;
+    implParams.boundary_phases = strToVec<Complex>(par().boundary);
+    implParams.twist_n_2pi_L   = strToVec<Real>(par().twist);
     envCreateDerived(FMat, MobiusFermion<FImpl>, getName(), par().Ls, U, g5,
                      grb5, g4, grb4, par().mass, par().M5, par().b, par().c,
                      implParams);
diff --git a/Hadrons/Modules/MAction/ScaledDWF.hpp b/Hadrons/Modules/MAction/ScaledDWF.hpp
index f7a09eef..3b8066e6 100644
--- a/Hadrons/Modules/MAction/ScaledDWF.hpp
+++ b/Hadrons/Modules/MAction/ScaledDWF.hpp
@@ -48,7 +48,8 @@ public:
                                     double      , mass,
                                     double      , M5,
                                     double      , scale,
-                                    std::string , boundary);
+                                    std::string , boundary,
+                                    std::string , twist);
 };
 
 template <typename FImpl>
@@ -118,8 +119,9 @@ void TScaledDWF<FImpl>::setup(void)
     auto &grb4 = *envGetRbGrid(FermionField);
     auto &g5   = *envGetGrid(FermionField, par().Ls);
     auto &grb5 = *envGetRbGrid(FermionField, par().Ls);
-    std::vector<Complex> boundary = strToVec<Complex>(par().boundary);
-    typename MobiusFermion<FImpl>::ImplParams implParams(boundary);
+    typename ScaledShamirFermion<FImpl>::ImplParams implParams;
+    implParams.boundary_phases = strToVec<Complex>(par().boundary);
+    implParams.twist_n_2pi_L   = strToVec<Real>(par().twist);
     envCreateDerived(FMat, ScaledShamirFermion<FImpl>, getName(), par().Ls, U, g5,
                      grb5, g4, grb4, par().mass, par().M5, par().scale,
                      implParams);
diff --git a/Hadrons/Modules/MAction/Wilson.hpp b/Hadrons/Modules/MAction/Wilson.hpp
index 093449e6..b5e53837 100644
--- a/Hadrons/Modules/MAction/Wilson.hpp
+++ b/Hadrons/Modules/MAction/Wilson.hpp
@@ -47,7 +47,9 @@ public:
     GRID_SERIALIZABLE_CLASS_MEMBERS(WilsonPar,
                                     std::string, gauge,
                                     double     , mass,
-                                    std::string, boundary);
+                                    std::string, boundary,
+                                    std::string, string,
+                                    std::string, twist);
 };
 
 template <typename FImpl>
@@ -113,8 +115,9 @@ void TWilson<FImpl>::setup(void)
     auto &U      = envGet(GaugeField, par().gauge);
     auto &grid   = *envGetGrid(FermionField);
     auto &gridRb = *envGetRbGrid(FermionField);
-    std::vector<Complex> boundary = strToVec<Complex>(par().boundary);
-    typename WilsonFermion<FImpl>::ImplParams implParams(boundary);
+    typename WilsonFermion<FImpl>::ImplParams implParams;
+    implParams.boundary_phases = strToVec<Complex>(par().boundary);
+    implParams.twist_n_2pi_L   = strToVec<Real>(par().twist);
     envCreateDerived(FMat, WilsonFermion<FImpl>, getName(), 1, U, grid, gridRb,
                      par().mass, implParams);
 }
diff --git a/Hadrons/Modules/MAction/WilsonClover.hpp b/Hadrons/Modules/MAction/WilsonClover.hpp
index 0b78bb55..ad301380 100644
--- a/Hadrons/Modules/MAction/WilsonClover.hpp
+++ b/Hadrons/Modules/MAction/WilsonClover.hpp
@@ -51,7 +51,8 @@ public:
 				                    double     , csw_r,
 				                    double     , csw_t,
 				                    WilsonAnisotropyCoefficients ,clover_anisotropy,
-                                    std::string, boundary
+                                    std::string, boundary,
+                                    std::string, twist
 				    );
 };
 
@@ -119,8 +120,9 @@ void TWilsonClover<FImpl>::setup(void)
     auto &U      = envGet(GaugeField, par().gauge);
     auto &grid   = *envGetGrid(FermionField);
     auto &gridRb = *envGetRbGrid(FermionField);
-    std::vector<Complex> boundary = strToVec<Complex>(par().boundary);
-    typename WilsonCloverFermion<FImpl>::ImplParams implParams(boundary);
+    typename WilsonCloverFermion<FImpl>::ImplParams implParams;
+    implParams.boundary_phases = strToVec<Complex>(par().boundary);
+    implParams.twist_n_2pi_L   = strToVec<Real>(par().twist);
     envCreateDerived(FMat, WilsonCloverFermion<FImpl>, getName(), 1, U, grid,
                      gridRb, par().mass, par().csw_r, par().csw_t, 
                      par().clover_anisotropy, implParams); 
diff --git a/Hadrons/Modules/MAction/ZMobiusDWF.hpp b/Hadrons/Modules/MAction/ZMobiusDWF.hpp
index 40b04d7f..12ad82ea 100644
--- a/Hadrons/Modules/MAction/ZMobiusDWF.hpp
+++ b/Hadrons/Modules/MAction/ZMobiusDWF.hpp
@@ -50,7 +50,8 @@ public:
                                     double                           , b,
                                     double                           , c,
                                     std::vector<std::complex<double>>, omega,
-                                    std::string                      , boundary);
+                                    std::string                      , boundary,
+                                    std::string                      , twist);
 };
 
 template <typename FImpl>
@@ -127,8 +128,9 @@ void TZMobiusDWF<FImpl>::setup(void)
     auto &g5   = *envGetGrid(FermionField, par().Ls);
     auto &grb5 = *envGetRbGrid(FermionField, par().Ls);
     auto omega = par().omega;
-    std::vector<Complex> boundary = strToVec<Complex>(par().boundary);
-    typename ZMobiusFermion<FImpl>::ImplParams implParams(boundary);
+    typename ZMobiusFermion<FImpl>::ImplParams implParams;
+    implParams.boundary_phases = strToVec<Complex>(par().boundary);
+    implParams.twist_n_2pi_L   = strToVec<Real>(par().twist);
     envCreateDerived(FMat, ZMobiusFermion<FImpl>, getName(), par().Ls, U, g5,
                      grb5, g4, grb4, par().mass, par().M5, omega,
                      par().b, par().c, implParams);
diff --git a/tests/hadrons/Test_QED.cc b/tests/hadrons/Test_QED.cc
index fb6f8198..9053c6ed 100644
--- a/tests/hadrons/Test_QED.cc
+++ b/tests/hadrons/Test_QED.cc
@@ -72,6 +72,7 @@ int main(int argc, char *argv[])
     
     // set fermion boundary conditions to be periodic space, antiperiodic time.
     std::string boundary = "1 1 1 -1";
+    std::string twist    = "0. 0. 0. 0.";
 
     //stochastic photon field
     MGauge::StochEm::Par photonPar;
@@ -90,6 +91,7 @@ int main(int argc, char *argv[])
         actionPar.M5    = 1.8;
         actionPar.mass  = mass[i];
         actionPar.boundary = boundary;
+        actionPar.twist = "0. 0. 0. 0.";
         application.createModule<MAction::DWF>("DWF_" + flavour[i], actionPar);
 
         
diff --git a/tests/hadrons/Test_hadrons.hpp b/tests/hadrons/Test_hadrons.hpp
index 1ee72356..7f07bea5 100644
--- a/tests/hadrons/Test_hadrons.hpp
+++ b/tests/hadrons/Test_hadrons.hpp
@@ -126,6 +126,7 @@ inline void makeWilsonAction(Application &application, std::string actionName,
         actionPar.gauge = gaugeField;
         actionPar.mass  = mass;
         actionPar.boundary = boundary;
+        actionPar.twist = "0. 0. 0. 0.";
         application.createModule<MAction::Wilson>(actionName, actionPar);
     }
 }
@@ -154,6 +155,7 @@ inline void makeDWFAction(Application &application, std::string actionName,
         actionPar.M5    = M5;
         actionPar.mass  = mass;
         actionPar.boundary = boundary;
+        actionPar.twist = "0. 0. 0. 0.";
         application.createModule<MAction::DWF>(actionName, actionPar);
     }
 }
diff --git a/tests/hadrons/Test_hadrons_meson_3pt.cc b/tests/hadrons/Test_hadrons_meson_3pt.cc
index 5b7cda22..741e2a7c 100644
--- a/tests/hadrons/Test_hadrons_meson_3pt.cc
+++ b/tests/hadrons/Test_hadrons_meson_3pt.cc
@@ -66,6 +66,7 @@ int main(int argc, char *argv[])
     
     // set fermion boundary conditions to be periodic space, antiperiodic time.
     std::string boundary = "1 1 1 -1";
+    std::string twist = "0. 0. 0. 0.";
 
     // sink
     MSink::Point::Par sinkPar;
@@ -80,6 +81,7 @@ int main(int argc, char *argv[])
         actionPar.M5    = 1.8;
         actionPar.mass  = mass[i];
         actionPar.boundary = boundary;
+        actionPar.twist = twist;
         application.createModule<MAction::DWF>("DWF_" + flavour[i], actionPar);
         
         // solvers
diff --git a/tests/hadrons/Test_hadrons_spectrum.cc b/tests/hadrons/Test_hadrons_spectrum.cc
index b57deb38..af1dccd7 100644
--- a/tests/hadrons/Test_hadrons_spectrum.cc
+++ b/tests/hadrons/Test_hadrons_spectrum.cc
@@ -72,6 +72,7 @@ int main(int argc, char *argv[])
     
     // set fermion boundary conditions to be periodic space, antiperiodic time.
     std::string boundary = "1 1 1 -1";
+    std::string twist = "0. 0. 0. 0.";
 
     for (unsigned int i = 0; i < flavour.size(); ++i)
     {
@@ -82,6 +83,7 @@ int main(int argc, char *argv[])
         actionPar.M5    = 1.8;
         actionPar.mass  = mass[i];
         actionPar.boundary = boundary;
+        actionPar.twist = twist;
         application.createModule<MAction::DWF>("DWF_" + flavour[i], actionPar);
         
         // solvers