diff --git a/src/libslic3r/MTUtils.hpp b/src/libslic3r/MTUtils.hpp
index e60918fab6..ab99ea5f68 100644
--- a/src/libslic3r/MTUtils.hpp
+++ b/src/libslic3r/MTUtils.hpp
@@ -47,7 +47,7 @@ private:
 public:
     // Forwarded constructor
     template<class... Args>
-    inline CachedObject(Setter fn, Args &&... args)
+    inline CachedObject(Setter &&fn, Args &&... args)
         : m_obj(std::forward<Args>(args)...), m_valid(false), m_setter(fn)
     {}
 
@@ -55,7 +55,7 @@ public:
     // the next retrieval (Setter will be called). The data that is used in
     // the setter function should be guarded as well during modification so
     // the modification has to take place in fn.
-    inline void invalidate(std::function<void()> fn)
+    template<class Fn> void invalidate(Fn &&fn)
     {
         std::lock_guard<SpinMutex> lck(m_lck);
         fn();
diff --git a/src/libslic3r/SLAPrint.cpp b/src/libslic3r/SLAPrint.cpp
index 004f7d5550..1bc5489145 100644
--- a/src/libslic3r/SLAPrint.cpp
+++ b/src/libslic3r/SLAPrint.cpp
@@ -138,14 +138,14 @@ Transform3d SLAPrint::sla_trafo(const ModelObject &model_object) const
     offset(1) = 0.;
     rotation(2) = 0.;
 
-    offset(Z) *= corr(Z);
+    offset.z() *= corr.z();
 
     auto trafo = Transform3d::Identity();
     trafo.translate(offset);
     trafo.scale(corr);
-    trafo.rotate(Eigen::AngleAxisd(rotation(2), Vec3d::UnitZ()));
-    trafo.rotate(Eigen::AngleAxisd(rotation(1), Vec3d::UnitY()));
-    trafo.rotate(Eigen::AngleAxisd(rotation(0), Vec3d::UnitX()));
+    trafo.rotate(Eigen::AngleAxisd(rotation.z(), Vec3d::UnitZ()));
+    trafo.rotate(Eigen::AngleAxisd(rotation.y(), Vec3d::UnitY()));
+    trafo.rotate(Eigen::AngleAxisd(rotation.x(), Vec3d::UnitX()));
     trafo.scale(model_instance.get_scaling_factor());
     trafo.scale(model_instance.get_mirror());