diff --git a/nifty5/minimization/energy_sum.py b/nifty5/minimization/energy_sum.py
index 0d0318013a95fbd2da5cc20224f4e1bc153bca80..67225c32472eec83dd6ac1c8bf1cb057cb608a30 100644
--- a/nifty5/minimization/energy_sum.py
+++ b/nifty5/minimization/energy_sum.py
@@ -37,6 +37,8 @@ class EnergySum(Energy):
         eout = []
         fout = []
         EnergySum._unpackEnergies(energies, factors, 1., eout, fout)
+        # FIXME we need to reach an agreement about how we want to deal
+        # with domain and field compatibility. Until then, we relax te check.
         # for e in eout[1:]:
         #     if not e.position.isEquivalentTo(eout[0].position):
         #         raise ValueError("position mismatch")