diff --git a/extras/Hadrons/Environment.cc b/extras/Hadrons/Environment.cc
index 68c170b8..37f2a3d7 100644
--- a/extras/Hadrons/Environment.cc
+++ b/extras/Hadrons/Environment.cc
@@ -41,8 +41,9 @@ using namespace Hadrons;
 // constructor /////////////////////////////////////////////////////////////////
 Environment::Environment(void)
 {
+    nd_ = GridDefaultLatt().size();
     grid4d_.reset(SpaceTimeGrid::makeFourDimGrid(
-        GridDefaultLatt(), GridDefaultSimd(Nd, vComplex::Nsimd()),
+        GridDefaultLatt(), GridDefaultSimd(nd_, vComplex::Nsimd()),
         GridDefaultMpi()));
     gridRb4d_.reset(SpaceTimeGrid::makeFourDimRedBlackGrid(grid4d_.get()));
     auto loc = getGrid()->LocalDimensions();
@@ -126,6 +127,11 @@ GridRedBlackCartesian * Environment::getRbGrid(const unsigned int Ls) const
     }
 }
 
+unsigned int Environment::getNd(void) const
+{
+    return nd_;
+}
+
 // random number generator /////////////////////////////////////////////////////
 void Environment::setSeed(const std::vector<int> &seed)
 {
diff --git a/extras/Hadrons/Environment.hpp b/extras/Hadrons/Environment.hpp
index 041bcc0e..2628e5a0 100644
--- a/extras/Hadrons/Environment.hpp
+++ b/extras/Hadrons/Environment.hpp
@@ -106,6 +106,7 @@ public:
     void                    createGrid(const unsigned int Ls);
     GridCartesian *         getGrid(const unsigned int Ls = 1) const;
     GridRedBlackCartesian * getRbGrid(const unsigned int Ls = 1) const;
+    unsigned int            getNd(void) const;
     // random number generator
     void                    setSeed(const std::vector<int> &seed);
     GridParallelRNG *       get4dRng(void) const;
@@ -200,6 +201,7 @@ private:
     std::map<unsigned int, GridPt>         grid5d_;
     GridRbPt                               gridRb4d_;
     std::map<unsigned int, GridRbPt>       gridRb5d_;
+    unsigned int                           nd_;
     // random number generator
     RngPt                                  rng4d_;
     // module and related maps
diff --git a/extras/Hadrons/Modules/MSource/SeqGamma.hpp b/extras/Hadrons/Modules/MSource/SeqGamma.hpp
index 181f9532..611b0108 100644
--- a/extras/Hadrons/Modules/MSource/SeqGamma.hpp
+++ b/extras/Hadrons/Modules/MSource/SeqGamma.hpp
@@ -147,7 +147,7 @@ void TSeqGamma<FImpl>::execute(void)
     g  = makeGammaProd(par().gamma);
     p  = strToVec<Real>(par().mom);
     ph = zero;
-    for(unsigned int mu = 0; mu < Nd; mu++)
+    for(unsigned int mu = 0; mu < env().getNd(); mu++)
     {
         LatticeCoordinate(coor, mu);
         ph = ph + p[mu]*coor;