diff --git a/tests/solver/Test_wilson_gmres_unprec.cc b/tests/solver/Test_wilson_gmres_unprec.cc
index 7ac20840..f371278c 100644
--- a/tests/solver/Test_wilson_gmres_unprec.cc
+++ b/tests/solver/Test_wilson_gmres_unprec.cc
@@ -52,7 +52,7 @@ int main (int argc, char ** argv)
   std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplex::Nsimd());
   std::vector<int> mpi_layout  = GridDefaultMpi();
   GridCartesian               Grid(latt_size,simd_layout,mpi_layout);
-  GridRedBlackCartesian     RBGrid(latt_size,simd_layout,mpi_layout);
+  GridRedBlackCartesian     RBGrid(&Grid);
 
   std::vector<int> seeds({1,2,3,4});
   GridParallelRNG          pRNG(&Grid);  pRNG.SeedFixedIntegers(seeds);