diff --git a/src/db/db/dbBox.h b/src/db/db/dbBox.h
index fae652597..7980917cc 100644
--- a/src/db/db/dbBox.h
+++ b/src/db/db/dbBox.h
@@ -1127,7 +1127,9 @@ box<C, R>::double_area () const
  */
 template <class Box>
 struct box_left 
+#if __cplusplus < 201703L
   : public std::unary_function<Box, typename Box::coord_type>
+#endif
 {
   typename Box::coord_type operator() (const Box &b) const
   {
@@ -1140,7 +1142,9 @@ struct box_left
  */
 template <class Box>
 struct box_right 
+#if __cplusplus < 201703L
   : public std::unary_function<Box, typename Box::coord_type>
+#endif
 {
   typename Box::coord_type operator() (const Box &b) const
   {
@@ -1153,7 +1157,9 @@ struct box_right
  */
 template <class Box>
 struct box_bottom 
+#if __cplusplus < 201703L
   : public std::unary_function<Box, typename Box::coord_type>
+#endif
 {
   typename Box::coord_type operator() (const Box &b) const
   {
@@ -1166,7 +1172,9 @@ struct box_bottom
  */
 template <class Box>
 struct box_top 
+#if __cplusplus < 201703L
   : public std::unary_function<Box, typename Box::coord_type>
+#endif
 {
   typename Box::coord_type operator() (const Box &b) const
   {
@@ -1179,7 +1187,9 @@ struct box_top
  */
 template <class Box>
 struct boxes_overlap
+#if __cplusplus < 201703L
   : public std::binary_function<Box, Box, bool>
+#endif
 {
   bool operator() (const Box &b1, const Box &b2) const
   {
@@ -1192,7 +1202,9 @@ struct boxes_overlap
  */
 template <class Box>
 struct boxes_touch
+#if __cplusplus < 201703L
   : public std::binary_function<Box, Box, bool>
+#endif
 {
   bool operator() (const Box &b1, const Box &b2) const
   {
diff --git a/src/db/db/dbBoxScanner.h b/src/db/db/dbBoxScanner.h
index e41b93a8a..4c658459d 100644
--- a/src/db/db/dbBoxScanner.h
+++ b/src/db/db/dbBoxScanner.h
@@ -44,7 +44,9 @@ namespace db
  */
 template <class BoxConvert, class Obj, class Prop, class SideOp>
 struct bs_side_compare_func
-  : std::binary_function<std::pair<const Obj *, Prop>, std::pair<const Obj *, Prop>, bool> 
+#if __cplusplus < 201703L
+  : std::binary_function<std::pair<const Obj *, Prop>, std::pair<const Obj *, Prop>, bool>
+#endif
 {
   typedef typename BoxConvert::box_type box_type;
 
@@ -69,7 +71,9 @@ private:
  */
 template <class BoxConvert, class Obj, class Prop, class SideOp>
 struct bs_side_compare_vs_const_func
-  : std::unary_function<std::pair<const Obj *, Prop>, bool> 
+#if __cplusplus < 201703L
+        : std::unary_function<std::pair<const Obj *, Prop>, bool>
+#endif
 {
   typedef typename BoxConvert::box_type box_type;
   typedef typename box_type::coord_type coord_type;
diff --git a/src/db/db/dbHierProcessor.cc b/src/db/db/dbHierProcessor.cc
index 3c9d1215e..583b15aae 100644
--- a/src/db/db/dbHierProcessor.cc
+++ b/src/db/db/dbHierProcessor.cc
@@ -327,6 +327,17 @@ local_processor_cell_context<TS, TI, TR>::local_processor_cell_context (const lo
   //  .. nothing yet ..
 }
 
+template <class TS, class TI, class TR>
+local_processor_cell_context<TS, TI, TR> &
+local_processor_cell_context<TS, TI, TR>::operator= (const local_processor_cell_context &other)
+{
+    if (this != &other) {
+        m_propagated = other.m_propagated;
+        m_drops = other.m_drops;
+    }
+    return *this;
+}
+
 template <class TS, class TI, class TR>
 void
 local_processor_cell_context<TS, TI, TR>::add (db::local_processor_cell_context<TS, TI, TR> *parent_context, db::Cell *parent, const db::ICplxTrans &cell_inst)
diff --git a/src/db/db/dbHierProcessor.h b/src/db/db/dbHierProcessor.h
index 502ec21ae..65895b3dc 100644
--- a/src/db/db/dbHierProcessor.h
+++ b/src/db/db/dbHierProcessor.h
@@ -164,6 +164,7 @@ public:
 
   local_processor_cell_context ();
   local_processor_cell_context (const local_processor_cell_context &other);
+  local_processor_cell_context &operator= (const local_processor_cell_context &other);
 
   void add (db::local_processor_cell_context<TS, TI, TR> *parent_context, db::Cell *parent, const db::ICplxTrans &cell_inst);
   void propagate (unsigned int layer, const std::unordered_set<TR> &res);
@@ -517,7 +518,6 @@ private:
   void issue_compute_contexts (db::local_processor_contexts<TS, TI, TR> &contexts, db::local_processor_cell_context<TS, TI, TR> *parent_context, db::Cell *subject_parent, db::Cell *subject_cell, const db::ICplxTrans &subject_cell_inst, const db::Cell *intruder_cell, typename local_processor_cell_contexts<TS, TI, TR>::context_key_type &intruders, db::Coord dist) const;
   void push_results (db::Cell *cell, unsigned int output_layer, const std::unordered_set<TR> &result) const;
   void compute_local_cell (const db::local_processor_contexts<TS, TI, TR> &contexts, db::Cell *subject_cell, const db::Cell *intruder_cell, const local_operation<TS, TI, TR> *op, const typename local_processor_cell_contexts<TS, TI, TR>::context_key_type &intruders, std::vector<std::unordered_set<TR> > &result) const;
-  std::pair<bool, db::CellInstArray> effective_instance (unsigned int subject_layer, db::cell_index_type subject_cell_index, unsigned int intruder_layer, db::cell_index_type intruder_cell_index, const db::ICplxTrans &ti2s, db::Coord dist) const;
 
   bool subject_cell_is_breakout (db::cell_index_type ci) const
   {
diff --git a/src/klayout.pri b/src/klayout.pri
index 01e08ba06..f1d6c9442 100644
--- a/src/klayout.pri
+++ b/src/klayout.pri
@@ -121,8 +121,13 @@ msvc {
 
   QMAKE_CXXFLAGS += \
       /bigobj \
-      /wd4251 \                   # Disable "DLL interface required"
-      /source-charset:utf-8 \     # Use UTF-8 for source files
+      /wd4251                     # Disable "DLL interface required"
+
+  lessThan(QT_MAJOR_VERSION, 6) {
+    # MSVC 2017 needs this option:
+    QMAKE_CXXFLAGS += \
+        /source-charset:utf-8 \     # Use UTF-8 for source files
+  }
 
   QMAKE_LFLAGS += \
       /OPT:NOREF \                # preserves functions we want to keep for implementing the "force link" mechanism