diff --git a/Solver/function.cpp b/Solver/function.cpp
index effa05277a494e3ae7c1a822c4d2a3cee370e5d3..47a6bdeed9e4fc2df41dc115fefdb6c17cc98753 100644
--- a/Solver/function.cpp
+++ b/Solver/function.cpp
@@ -38,7 +38,7 @@ void function::setArgument(fullMatrix<double> &v, const function *f, int iMap)
       Msg::Error("Consecutive secondary caches");
     dependencies.insert(dependency(iMap + it->iMap, it->f));
   }
-  for (int i = 0; i < _functionReplaces.size(); i++) {
+  for (unsigned int i = 0; i < _functionReplaces.size(); i++) {
     functionReplace &replace = *_functionReplaces[i];
     for (std::set<dependency>::iterator it = replace._fromParent.begin(); 
          it != replace._fromParent.end(); it++) {