diff --git a/gtsam/hybrid/GaussianMixtureFactor.cpp b/gtsam/hybrid/GaussianMixtureFactor.cpp
index 657ef334b..57f42e6f1 100644
--- a/gtsam/hybrid/GaussianMixtureFactor.cpp
+++ b/gtsam/hybrid/GaussianMixtureFactor.cpp
@@ -91,14 +91,6 @@ double GaussianMixtureFactor::constant(const DiscreteValues &assignment) const {
   return factors_(assignment).constant;
 }
 
-/* *******************************************************************************/
-// NOTE(dellaert): this was not used and is expensive.
-// const GaussianMixtureFactor::Mixture GaussianMixtureFactor::factors() const {
-//   return Mixture(factors_, [](const FactorAndConstant &factor_z) {
-//     return factor_z.factor;
-//   });
-// }
-
 /* *******************************************************************************/
 GaussianFactorGraphTree GaussianMixtureFactor::add(
     const GaussianFactorGraphTree &sum) const {