diff --git a/.github/workflows/cppcheck.yml b/.github/workflows/cppcheck.yml
index e74ef8f7f..e66f20f30 100644
--- a/.github/workflows/cppcheck.yml
+++ b/.github/workflows/cppcheck.yml
@@ -29,9 +29,7 @@ jobs:
           cmake --build 'eigen/build' --parallel 4
           sudo cmake --install 'eigen/build' )
         ( cd /tmp
-          git clone https://github.com/danmar/cppcheck.git
-          ( cd cppcheck
-            git checkout fa561e9c242e7ceeb16408ef55e8bcea04fcf46f )
+          git clone --depth 1 'https://github.com/danmar/cppcheck.git'
           cmake -S 'cppcheck' -B 'cppcheck/build'
           cmake --build 'cppcheck/build' --parallel 4
           sudo cmake --install 'cppcheck/build' )
diff --git a/include/fcarouge/internal/kalman.tpp b/include/fcarouge/internal/kalman.tpp
index e99e4c865..14ee6f664 100644
--- a/include/fcarouge/internal/kalman.tpp
+++ b/include/fcarouge/internal/kalman.tpp
@@ -224,16 +224,6 @@ kalman<Filter>::s() const -> const innovation_uncertainty & {
   return filter.s;
 }
 
-template <typename Filter>
-inline constexpr void kalman<Filter>::transition(const auto &callable) {
-  filter.transition = callable;
-}
-
-template <typename Filter>
-inline constexpr void kalman<Filter>::observation(const auto &callable) {
-  filter.observation = callable;
-}
-
 template <typename Filter>
 inline constexpr void kalman<Filter>::update(const auto &...arguments) {
   filter.update(arguments...);
diff --git a/include/fcarouge/kalman.hpp b/include/fcarouge/kalman.hpp
index c04a74369..72e90ae2b 100644
--- a/include/fcarouge/kalman.hpp
+++ b/include/fcarouge/kalman.hpp
@@ -492,34 +492,6 @@ class kalman final : public internal::conditional_member_types<Filter> {
   //!
   //! @complexity Constant.
   inline constexpr auto s() const -> const innovation_uncertainty &;
-
-  //! @brief Sets the extended state transition function f(x).
-  //!
-  //! @param callable The copied target Callable object (function object,
-  //! pointer to function, reference to function, pointer to member function, or
-  //! pointer to data member) that will be called to compute the next state X on
-  //! prediction steps of expression `state(const state &, const input &, const
-  //! PredictionTypes &...)`. The default function `f(x) = F * X` is suitable
-  //! for linear systems. For non-linear system, or extended filter, implement a
-  //! linearization of the transition function f and the state transition F
-  //! matrix is the Jacobian of the state transition function.
-  //!
-  //! @complexity Constant.
-  inline constexpr void transition(const auto &callable);
-
-  //! @brief Sets the extended state observation function h(x).
-  //!
-  //! @param callable The copied target Callable object (function object,
-  //! pointer to function, reference to function, pointer to member function, or
-  //! pointer to data member) that will be called to compute the observation Z
-  //! on update steps of expression `output(const state &, const UpdateTypes
-  //! &...arguments)`. The default function `h(x) = H * X` is suitable for
-  //! linear systems. For non-linear system, or extended filter, the client
-  //! implements a linearization of the observation function hand the state
-  //! observation H matrix is the Jacobian of the state observation function.
-  //!
-  //! @complexity Constant.
-  inline constexpr void observation(const auto &callable);
   //! @}
 
   //! @name Public Filtering Member Functions