diff --git a/zoidberg/zoidberg.py b/zoidberg/zoidberg.py
index 176605b..6985c20 100644
--- a/zoidberg/zoidberg.py
+++ b/zoidberg/zoidberg.py
@@ -174,9 +174,13 @@ def make_maps(grid, magnetic_field, nslice=1, quiet=False, field_tracer=None, **
                     xind, zind = pol_slice.findIndex(xcoord, zcoord)
 
                     # Check boundary defined by the field
-                    outside = magnetic_field.boundary.outside(xcoord, y_slice, zcoord)
-                    xind[outside] = -1
-                    zind[outside] = -1
+
+                    if hasattr(magnetic_field, "boundary"):
+                        outside = magnetic_field.boundary.outside(
+                            xcoord, y_slice, zcoord
+                        )
+                        xind[outside] = -1
+                        zind[outside] = -1
 
                 parallel_slice.xt_prime[:, j, :] = xind
                 parallel_slice.zt_prime[:, j, :] = zind