--- a/LundPlane/example_dpsi_slice.cc
+++ b/LundPlane/example_dpsi_slice.cc
@@ -124,7 +124,7 @@
 
   int index_of_max_kt_secondary = -1;
   double dpsi;
-  for (uint i_secondary=0; i_secondary<secondaries.size(); i_secondary++) {
+  for (unsigned int i_secondary=0; i_secondary<secondaries.size(); i_secondary++) {
     if (secondaries[i_secondary]->z() > z2_cut) {
 
       index_of_max_kt_secondary = i_secondary;