diff --git a/dune/gfe/localgeodesicfestiffness.hh b/dune/gfe/localgeodesicfestiffness.hh
index fb918b1fec8c9edb8f6c910c9e5366ea4467353f..39da5b43c382452349a605a7db0aebdda2345dd6 100644
--- a/dune/gfe/localgeodesicfestiffness.hh
+++ b/dune/gfe/localgeodesicfestiffness.hh
@@ -266,7 +266,7 @@ assembleHessian(const Entity& element,
     // ///////////////////////////////////////////////////////////////
     //   Loop over all blocks of the element matrix
     // ///////////////////////////////////////////////////////////////
-    for (int i=0; i<A_.N(); i++) {
+    for (size_t i=0; i<A_.N(); i++) {
 
         ColumnIterator cIt    = A_[i].begin();
         ColumnIterator cEndIt = A_[i].end();
@@ -354,7 +354,7 @@ assembleHessian(const Entity& element,
     //   This is possible expensive, but I want to be absolute sure
     //   that the matrix is symmetric.
     // ///////////////////////////////////////////////////////////////
-    for (int i=0; i<A_.N(); i++) {
+    for (size_t i=0; i<A_.N(); i++) {
 
         ColumnIterator cIt    = A_[i].begin();
         ColumnIterator cEndIt = A_[i].end();