diff --git a/Applications/FileIO/Legacy/OGSIOVer4.cpp b/Applications/FileIO/Legacy/OGSIOVer4.cpp
index cfd58b39a8d83816a0c7f20185095b66f35441ef..763cebfd9f454b60cf42955b6b8c0b53171cded6 100644
--- a/Applications/FileIO/Legacy/OGSIOVer4.cpp
+++ b/Applications/FileIO/Legacy/OGSIOVer4.cpp
@@ -735,7 +735,7 @@ void writeAllDataToGLIFileV4(const std::string& fname,
     // writing all points
     os << "#POINTS"
        << "\n";
-    for (auto& geo_name : geo_names)
+    for (auto const& geo_name : geo_names)
     {
         os.precision(std::numeric_limits<double>::digits10);
         GeoLib::PointVec const* const pnt_vec(geo.getPointVecObj(geo_name));
diff --git a/GeoLib/AnalyticalGeometry-impl.h b/GeoLib/AnalyticalGeometry-impl.h
index 6838ed5a81f31c35ca7440ce0b50ac23e414fb77..c908962516e029116b538ce9d8a637a42ed6f07d 100644
--- a/GeoLib/AnalyticalGeometry-impl.h
+++ b/GeoLib/AnalyticalGeometry-impl.h
@@ -17,8 +17,8 @@ std::pair<Eigen::Vector3d, double> getNewellPlane(InputIterator pnts_begin,
     Eigen::Vector3d plane_normal({0, 0, 0});
     Eigen::Vector3d centroid({0, 0, 0});
     for (auto i=std::prev(pnts_end), j=pnts_begin; j!=pnts_end; i = j, ++j) {
-        auto &pt_i = *(*i);
-        auto &pt_j = *(*j);
+        auto const& pt_i = *(*i);
+        auto const& pt_j = *(*j);
         plane_normal[0] += (pt_i[1] - pt_j[1])
                            * (pt_i[2] + pt_j[2]); // projection on yz
         plane_normal[1] += (pt_i[2] - pt_j[2])
diff --git a/NumLib/DOF/SimpleMatrixVectorProvider.cpp b/NumLib/DOF/SimpleMatrixVectorProvider.cpp
index 012ff6589f75b38d352a12c98b11b0f276d5d195..c777b3b186aa28bb0397a7c92b90bb98770f2685 100644
--- a/NumLib/DOF/SimpleMatrixVectorProvider.cpp
+++ b/NumLib/DOF/SimpleMatrixVectorProvider.cpp
@@ -151,12 +151,12 @@ SimpleMatrixVectorProvider::~SimpleMatrixVectorProvider()
             _used_vectors.size());
     }
 
-    for (auto& ptr_id : _used_matrices)
+    for (auto const& ptr_id : _used_matrices)
     {
         delete ptr_id.first;
     }
 
-    for (auto& ptr_id : _used_vectors)
+    for (auto const& ptr_id : _used_vectors)
     {
         delete ptr_id.first;
     }