diff --git a/Core/include/Acts/EventData/SingleFreeParameters.hpp b/Core/include/Acts/EventData/SingleFreeParameters.hpp
index def1eeba74edbf78df5629d92889a9994491ffc0..890f274b31d2c3a86b31a8d6f26271ec11a95330 100644
--- a/Core/include/Acts/EventData/SingleFreeParameters.hpp
+++ b/Core/include/Acts/EventData/SingleFreeParameters.hpp
@@ -7,11 +7,10 @@
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 #pragma once
-// STL include(s)
+
 #include <iomanip>
 #include <ostream>
 
-// Acts includes
 #include "Acts/EventData/detail/coordinate_transformations.hpp"
 #include "Acts/Utilities/Definitions.hpp"
 
@@ -55,7 +54,7 @@ class SingleFreeParameters {
   SingleFreeParameters(std::optional<CovMatrix_t> cov,
                        const FreeVector& parValues)
       : m_parameters(parValues),
-        m_oChargePolicy((parValues(FreeParsDim - 1) > 0.) ? 1. : -1.),
+        m_oChargePolicy((0 < parValues(eFreeQOverP)) ? 1. : -1.),
         m_covariance(std::move(cov)) {}
 
   /// @brief Standard constructor for track parameters of neutral particles
@@ -137,7 +136,8 @@ class SingleFreeParameters {
   ///
   /// @return Value of the requested parameter
   template <unsigned int par,
-            std::enable_if_t<par<FreeParsDim, int> = 0> ParValue_t get() const {
+            std::enable_if_t<par<eFreeParametersSize, int> = 0> ParValue_t get()
+                const {
     return m_parameters(par);
   }
 
@@ -147,8 +147,9 @@ class SingleFreeParameters {
   /// retrieved
   ///
   /// @return Value of the requested parameter uncertainty
-  template <unsigned int par, std::enable_if_t<par<FreeParsDim, int> = 0>
-                                  ParValue_t uncertainty() const {
+  template <unsigned int par,
+            std::enable_if_t<par<eFreeParametersSize, int> = 0> ParValue_t
+                uncertainty() const {
     return std::sqrt(m_covariance->coeff(par, par));
   }
 
@@ -227,7 +228,7 @@ class SingleFreeParameters {
   /// @note The context is not used here but makes the API consistent with @c
   /// SingleCurvilinearTrackParameters and @c SingleBoundTrackParameters
   template <unsigned int par,
-            std::enable_if_t<par<FreeParsDim, int> = 0> void set(
+            std::enable_if_t<par<eFreeParametersSize, int> = 0> void set(
                 const GeometryContext& /*gctx*/, ParValue_t newValue) {
     m_parameters(par) = newValue;
   }
@@ -279,4 +280,4 @@ class SingleFreeParameters {
   std::optional<CovMatrix_t> m_covariance;  ///< Covariance matrix
 };
 
-}  // namespace Acts
\ No newline at end of file
+}  // namespace Acts
diff --git a/Core/include/Acts/Utilities/ParameterDefinitions.hpp b/Core/include/Acts/Utilities/ParameterDefinitions.hpp
index 897874ad7565b856a54d938ba015da72f5246ef3..6a281436eeeca628c148a5271e2583a6f40197c6 100644
--- a/Core/include/Acts/Utilities/ParameterDefinitions.hpp
+++ b/Core/include/Acts/Utilities/ParameterDefinitions.hpp
@@ -310,6 +310,5 @@ using par_type_t = typename detail::BoundParameterTraits<kIndex>::type;
 // For backward compatibility. New code must use the
 // `e{BoundParameters,FreeParameters,SpacePoint}Size` enum values.
 inline constexpr unsigned int BoundParsDim = eBoundParametersSize;
-inline constexpr unsigned int FreeParsDim = eFreeParametersSize;
 
 }  // namespace Acts
diff --git a/Tests/UnitTests/Core/Propagator/JacobianTests.cpp b/Tests/UnitTests/Core/Propagator/JacobianTests.cpp
index 30c18484a160e386c660b7037ce70d84bcbb00d9..ab7fc6421702e39228337baa3d6001fa61582c5a 100644
--- a/Tests/UnitTests/Core/Propagator/JacobianTests.cpp
+++ b/Tests/UnitTests/Core/Propagator/JacobianTests.cpp
@@ -108,9 +108,9 @@ std::shared_ptr<Transform3D> createPlanarTransform(const Vector3D& nposition,
 BoundToFreeMatrix convertToMatrix(const std::array<double, 60> P) {
   // initialize to zero
   BoundToFreeMatrix jMatrix = BoundToFreeMatrix::Zero();
-  for (size_t j = 0; j < BoundParsDim; ++j) {
-    for (size_t i = 0; i < FreeParsDim; ++i) {
-      size_t ijc = FreeParsDim + j * FreeParsDim + i;
+  for (size_t j = 0; j < eBoundParametersSize; ++j) {
+    for (size_t i = 0; i < eFreeParametersSize; ++i) {
+      size_t ijc = eFreeParametersSize + j * eFreeParametersSize + i;
       jMatrix(i, j) = P[ijc];
     }
   }