diff --git a/lib/Statistics/XYSampleData.cpp b/lib/Statistics/XYSampleData.cpp
index ae5edba..73e5e51 100644
--- a/lib/Statistics/XYSampleData.cpp
+++ b/lib/Statistics/XYSampleData.cpp
@@ -234,6 +234,12 @@ DVec XYSampleData::getYError(const Index j)
     return data_.getYError(j);
 }
 
+void XYSampleData::setChi2PerDofBound(double upper_lim, double lower_lim)
+{
+    chi2PerDofu_ = upper_lim;
+    chi2PerDofl_ = lower_lim;
+}
+
 bool XYSampleData::checkFit()
 {
     return goodFit_;
@@ -241,7 +247,7 @@ bool XYSampleData::checkFit()
 
 void XYSampleData::checkChi2PerDof(double Chi2PerDof)
 {
-    if(Chi2PerDof >= 2 or Chi2PerDof < 0 or isnan(Chi2PerDof)) 
+    if(Chi2PerDof >= chi2PerDofu_ or Chi2PerDof < chi2PerDofl_ or isnan(Chi2PerDof)) 
     {
         goodFit_ = false;
     }
diff --git a/lib/Statistics/XYSampleData.hpp b/lib/Statistics/XYSampleData.hpp
index a66c9dd..a18103a 100644
--- a/lib/Statistics/XYSampleData.hpp
+++ b/lib/Statistics/XYSampleData.hpp
@@ -91,6 +91,8 @@ public:
     const DMat &       getXYVar(const Index i, const Index j);
     DVec               getXError(const Index i);
     DVec               getYError(const Index j);
+    // fit criteria
+    void               setChi2PerDofBound(double upper_lim, double lower_lim);
     bool               checkFit(); // check fit candidate based on chi2PerDof
     void               checkChi2PerDof(double Chi2PerDof);
     // get total fit variance matrix and its pseudo-inverse
@@ -136,6 +138,7 @@ private:
     bool                                  initData_{true}, computeVarMat_{true};
     bool                                  initXMap_{true};
     bool                                  goodFit_{true}; // used to break minimisation if central sample chi2PerDof is bad
+    double                                chi2PerDofu_{1e10}, chi2PerDofl_{0};
 };
 
 /******************************************************************************