diff --git a/Modules/Learning/Supervised/include/otbCvRTreesWrapper.h b/Modules/Learning/Supervised/include/otbCvRTreesWrapper.h
index 47f4560293717df9e2da1693069924b08c659901..205d4e7cc2e56c1c9dd98a86478442060b4dddd1 100644
--- a/Modules/Learning/Supervised/include/otbCvRTreesWrapper.h
+++ b/Modules/Learning/Supervised/include/otbCvRTreesWrapper.h
@@ -57,7 +57,7 @@ public:
       }
     // We only sort the 2 greatest elements
     std::nth_element(classVotes.begin(), classVotes.begin()+1, 
-                     classVotes.end(), std::greater<>());
+                     classVotes.end(), std::greater<unsigned int>());
     float confidence = static_cast<float>(classVotes[0]-classVotes[1])/ntrees;
     return confidence;
   };