diff --git a/Physlib/Particles/BeyondTheStandardModel/TwoHDM/Potential.lean b/Physlib/Particles/BeyondTheStandardModel/TwoHDM/Potential.lean
index 709e0d5a5..1c95af4de 100644
--- a/Physlib/Particles/BeyondTheStandardModel/TwoHDM/Potential.lean
+++ b/Physlib/Particles/BeyondTheStandardModel/TwoHDM/Potential.lean
@@ -453,6 +453,9 @@ lemma potential_eq_gramVector (P : PotentialParameters) (H : TwoHiggsDoublet) :
     ∑ a, ∑ b, H.gramVector a * H.gramVector b * P.η a b := by
   rw [potential, massTerm_eq_gramVector, quarticTerm_eq_gramVector]
 
+TODO "Define a general effective potential for the two Higgs doublet model, mirroring
+  `StandardModel.HiggsField.EffectivePotential`"
+
 /-!
 
 ## E. Stability of the potential