diff --git a/reco/detectors/sts/CbmStsAlgoFindHits.cxx b/reco/detectors/sts/CbmStsAlgoFindHits.cxx
index 3863eb23fe3b8225a9d111fbfb7fc705b7b61c17..fa88a5fd03013656f2b51dcf91ae5b38ed9655d1 100644
--- a/reco/detectors/sts/CbmStsAlgoFindHits.cxx
+++ b/reco/detectors/sts/CbmStsAlgoFindHits.cxx
@@ -116,7 +116,7 @@ Long64_t CbmStsAlgoFindHits::Exec(const vector<CbmStsCluster>& clustersF,
   fHits->clear();
   fTanStereoF = TMath::Tan(fStereoF * TMath::DegToRad());
   fTanStereoB = TMath::Tan(fStereoB * TMath::DegToRad());
-  fErrorFac   = 1. / (fTanStereoB - fTanStereoF) / (fTanStereoB - fTanStereoB);
+  fErrorFac   = 1. / (fTanStereoB - fTanStereoF) / (fTanStereoB - fTanStereoF);
   fDx         = Double_t(fNofStrips) * fPitch;
 
   // Determine the maximum cluster time errors