diff --git a/interface/GeneralFunctions.hpp b/interface/GeneralFunctions.hpp
index ec19c5a7ebde2..180d3f5be6253 100644
--- a/interface/GeneralFunctions.hpp
+++ b/interface/GeneralFunctions.hpp
@@ -27,7 +27,8 @@ namespace ChargedHiggs{
     float mt(const float pt1, const float pt2, const float phi1, const float phi2);
     // compute mt2
     float mt2( const TLorentzVector visa,  const TLorentzVector visb,  const TLorentzVector metVec);
-
+    // compute general functions Fox-Wolfram momenta
+    float FW_momentum( const std::vector<TLorentzVector> jet, int index);
 
     // use this for massive objects
     template <typename T>