diff --git a/Source/FieldSolver/ElectrostaticSolvers/RelativisticExplicitES.cpp b/Source/FieldSolver/ElectrostaticSolvers/RelativisticExplicitES.cpp
index e1965706da1..4fdf2d0789a 100644
--- a/Source/FieldSolver/ElectrostaticSolvers/RelativisticExplicitES.cpp
+++ b/Source/FieldSolver/ElectrostaticSolvers/RelativisticExplicitES.cpp
@@ -30,7 +30,9 @@ RelativisticExplicitES::ComputeSpaceChargeField (
     }
 
     // Add the field due to the boundary potentials
-    AddBoundaryField(Efield_fp, Bfield_fp);
+    if (m_poisson_boundary_handler->m_boundary_potential_specified) {
+        AddBoundaryField(Efield_fp, Bfield_fp);
+    }
 }
 
 void