diff --git a/source/FinalWaveFunc.cpp b/source/FinalWaveFunc.cpp
index 20573b6fca6450ab0a10d4c334c03923120a6645..c6bf35aa9835e69b1da3db9be438dd1b03f74036 100644
--- a/source/FinalWaveFunc.cpp
+++ b/source/FinalWaveFunc.cpp
@@ -58,8 +58,7 @@ double finalWaveFunc::computeNorm(double rMax) {
 
 double DCAP::computeSquareWellDepth(shared_ptr<ParticleChannel>& channel, double energy, 
     double energyMin, double energyMax) {
-    double r = channel->getChannelRadius();
-    LogDerivDiff fobj(channel, energy, r);
+    LogDerivDiff fobj(channel, energy);
     TF1 * f = new TF1("f", fobj, energyMin-10, energyMax+10, 0);
     ROOT::Math::WrappedTF1 wf(*f);
     ROOT::Math::BrentRootFinder brf;
diff --git a/source/LogDerivDiff.cpp b/source/LogDerivDiff.cpp
index e45fbccea8a3b8c531fd334ce867ed47ba504184..f5e0a3d830a6e9ef8418ab5e13702585fcb5d1d2 100644
--- a/source/LogDerivDiff.cpp
+++ b/source/LogDerivDiff.cpp
@@ -23,8 +23,9 @@ using namespace ORM;
 using namespace DCAP;
 
 
-LogDerivDiff::LogDerivDiff(shared_ptr<ParticleChannel>& channel, double energy, double radius) 
-    : channel(channel), E(energy), r(radius) {
+LogDerivDiff::LogDerivDiff(shared_ptr<ParticleChannel>& channel, double energy) 
+    : channel(channel), E(energy) {
+    double r = channel->getChannelRadius();
     double W = channel->whittakerFunction(E);
     double dWdr = channel->whittakerFunctionDerivative(E);
     lhs = 1./(W/r) * (1./r*dWdr - W/(r*r));