diff --git a/Core/include/Acts/TrackFitting/BetheHeitlerApprox.hpp b/Core/include/Acts/TrackFitting/BetheHeitlerApprox.hpp
index 373f5b11ea6..5d0c5601bea 100644
--- a/Core/include/Acts/TrackFitting/BetheHeitlerApprox.hpp
+++ b/Core/include/Acts/TrackFitting/BetheHeitlerApprox.hpp
@@ -87,7 +87,7 @@ struct BetheHeitlerApproxSingleCmp {
 
     ret[0].weight = 1.0;
 
-    const double c = x / std::numbers::sqrt2;
+    const double c = x / std::numbers::ln2;
     ret[0].mean = std::pow(2, -c);
     ret[0].var = std::pow(3, -c) - std::pow(4, -c);