diff --git a/corsika/stack/NuclearStackExtension.hpp b/corsika/stack/NuclearStackExtension.hpp
index 445350506811ece92db3697c72d96b4b52c2c5f5..d65e654bde037d2cb37d392339510ec5a3aad006 100644
--- a/corsika/stack/NuclearStackExtension.hpp
+++ b/corsika/stack/NuclearStackExtension.hpp
@@ -101,7 +101,7 @@ namespace corsika::nuclear_stack {
     /**
      * Overwrite normal getKineticEnergy function with nuclear version
      */
-    HEPMassType getKineticEnergy() const;
+    HEPEnergyType getKineticEnergy() const;
 
     /**
      * Overwirte normal getChargeNumber function with nuclear version