diff --git a/Core/include/Acts/Propagator/DefaultExtension.hpp b/Core/include/Acts/Propagator/DefaultExtension.hpp
index 66a4f8f2ee5e4746cd130072c80c028e17fd7be6..c1cddc578fa76f157ef9218c24fb353b33a8a660 100644
--- a/Core/include/Acts/Propagator/DefaultExtension.hpp
+++ b/Core/include/Acts/Propagator/DefaultExtension.hpp
@@ -38,6 +38,7 @@ struct DefaultExtension {
   /// @param [in] stepper Stepper of the propagation
   /// @param [out] knew Next k_i that is evaluated
   /// @param [in] bField B-Field at the evaluation position
+  /// @param [out] kQoP k_i elements of the momenta
   /// @param [in] i Index of the k_i, i = [0, 3]
   /// @param [in] h Step size (= 0. ^ 0.5 * StepSize ^ StepSize)
   /// @param [in] kprev Evaluated k_{i - 1}
diff --git a/Core/include/Acts/Propagator/DenseEnvironmentExtension.hpp b/Core/include/Acts/Propagator/DenseEnvironmentExtension.hpp
index 8ace9614587480e3f7d7ef794b6fcf2b8d2f38b1..9608a7dcd7da622fb9d6cb7a0e391cc31cde5036 100644
--- a/Core/include/Acts/Propagator/DenseEnvironmentExtension.hpp
+++ b/Core/include/Acts/Propagator/DenseEnvironmentExtension.hpp
@@ -79,6 +79,7 @@ struct DenseEnvironmentExtension {
   /// @tparam stepper_t Type of the stepper
   /// @param [in] state State of the propagator
   /// @param [out] knew Next k_i that is evaluated
+  /// @param [out] kQoP k_i elements of the momenta
   /// @param [in] bField B-Field at the evaluation position
   /// @param [in] i Index of the k_i, i = [0, 3]
   /// @param [in] h Step size (= 0. ^ 0.5 * StepSize ^ StepSize)