diff --git a/src/libslic3r/Print.cpp b/src/libslic3r/Print.cpp
index 7e196c85f..0ec88c44f 100644
--- a/src/libslic3r/Print.cpp
+++ b/src/libslic3r/Print.cpp
@@ -1229,7 +1229,7 @@ void Print::alert_when_supports_needed()
             }
 
             std::string translated_list = expansion_rule;
-            for (int i = 0; i < translated_elements.size() - 1; i++) {
+            for (int i = 0; i < int(translated_elements.size()) - 1; ++ i) {
                 auto first_elem = translated_list.find("%1%");
                 assert(first_elem != translated_list.npos);
                 translated_list.replace(first_elem, 3, translated_elements[i]);
@@ -1237,7 +1237,7 @@ void Print::alert_when_supports_needed()
                 // expand the translated list by another application of the same rule
                 auto second_elem = translated_list.find("%2%");
                 assert(second_elem != translated_list.npos);
-                if (i < translated_elements.size() - 2) {
+                if (i < int(translated_elements.size()) - 2) {
                     translated_list.replace(second_elem, 3, expansion_rule);
                 } else {
                     translated_list.replace(second_elem, 3, translated_elements[i + 1]);
diff --git a/src/libslic3r/Support/TreeSupport.cpp b/src/libslic3r/Support/TreeSupport.cpp
index 06fff4fe7..051f6cbb1 100644
--- a/src/libslic3r/Support/TreeSupport.cpp
+++ b/src/libslic3r/Support/TreeSupport.cpp
@@ -387,6 +387,7 @@ static std::vector<std::pair<TreeSupportSettings, std::vector<size_t>>> group_me
     return result;
 }
 
+#if 0
 /*!
  * \brief Converts lines in internal format into a Polygons object representing these lines.
  *
@@ -405,6 +406,7 @@ static std::vector<std::pair<TreeSupportSettings, std::vector<size_t>>> group_me
     validate_range(result);
     return result;
 }
+#endif
 
 /*!
  * \brief Evaluates if a point has to be added now. Required for a split_lines call in generate_initial_areas().
@@ -788,7 +790,7 @@ static std::optional<std::pair<Point, size_t>> polyline_sample_next_point_at_dis
         else
             do_final_difference = true;
     }
-    if (steps + (distance < last_step_offset_without_check || distance % step_size != 0) < min_amount_offset && min_amount_offset > 1) {
+    if (steps + (distance < last_step_offset_without_check || (distance % step_size) != 0) < int(min_amount_offset) && min_amount_offset > 1) {
         // yes one can add a bool as the standard specifies that a result from compare operators has to be 0 or 1
         // reduce the stepsize to ensure it is offset the required amount of times
         step_size = distance / min_amount_offset;
@@ -2611,13 +2613,13 @@ static void remove_deleted_elements(std::vector<SupportElements> &move_bounds)
                     std::iota(map_current.begin(), map_current.end(), 0);
                 }
                 // Delete all "deleted" elements from the end of the layer vector.
-                while (i < layer.size() && layer.back().state.deleted) {
+                while (i < int32_t(layer.size()) && layer.back().state.deleted) {
                     layer.pop_back();
                     // Mark as deleted in the map.
                     map_current[layer.size()] = -1;
                 }
                 assert(i == layer.size() || i + 1 < layer.size());
-                if (i + 1 < layer.size()) {
+                if (i + 1 < int32_t(layer.size())) {
                     element = std::move(layer.back());
                     layer.pop_back();                    
                     // Mark the current element as deleted.
@@ -2667,7 +2669,7 @@ static void create_nodes_from_area(
 
     for (LayerIndex layer_idx = 1; layer_idx < LayerIndex(move_bounds.size()); ++ layer_idx) {
         auto &layer       = move_bounds[layer_idx];
-        auto *layer_above = layer_idx + 1 < move_bounds.size() ? &move_bounds[layer_idx + 1] : nullptr;
+        auto *layer_above = layer_idx + 1 < LayerIndex(move_bounds.size()) ? &move_bounds[layer_idx + 1] : nullptr;
         if (layer_above)
             for (SupportElement &elem : *layer_above)
                 elem.state.marked = false;
@@ -2809,7 +2811,7 @@ static void generate_branch_areas(
                     const Point movement = draw_area.child_element->state.result_on_layer - draw_area.element->state.result_on_layer;
                     movement_directions.emplace_back(movement, radius);
                 }
-                const SupportElements *layer_above = layer_idx + 1 < move_bounds.size() ? &move_bounds[layer_idx + 1] : nullptr;
+                const SupportElements *layer_above = layer_idx + 1 < LayerIndex(move_bounds.size()) ? &move_bounds[layer_idx + 1] : nullptr;
                 for (int32_t parent_idx : draw_area.element->parents) {
                     const SupportElement &parent = (*layer_above)[parent_idx];
                     const Point movement = parent.state.result_on_layer - draw_area.element->state.result_on_layer;
@@ -3255,7 +3257,7 @@ static void draw_areas(
         std::vector<std::pair<SupportElement*, SupportElement*>> map_downwards_old;
         std::vector<std::pair<SupportElement*, SupportElement*>> map_downwards_new;
         for (LayerIndex layer_idx = 0; layer_idx < LayerIndex(move_bounds.size()); ++ layer_idx) {
-            SupportElements *layer_above = layer_idx + 1 < move_bounds.size() ? &move_bounds[layer_idx + 1] : nullptr;
+            SupportElements *layer_above = layer_idx + 1 < LayerIndex(move_bounds.size()) ? &move_bounds[layer_idx + 1] : nullptr;
             map_downwards_new.clear();
             linear_data_layers.emplace_back(linear_data.size());
             std::sort(map_downwards_old.begin(), map_downwards_old.end(), [](auto &l, auto &r) { return l.first < r.first;  });