diff --git a/include/plugins/converters.h b/include/plugins/converters.h
index 9f76c71b5f..01870b2056 100644
--- a/include/plugins/converters.h
+++ b/include/plugins/converters.h
@@ -87,7 +87,7 @@ struct simplify_request : public details::converter<simplify_request, slots::sim
 
 struct simplify_response : public details::converter<simplify_response, slots::simplify::v0::modify::CallResponse, Polygons>
 {
-    native_value_type operator()([[maybe_unused]] native_value_type& original_value, const value_type& message) const;
+    native_value_type operator()([[maybe_unused]] const native_value_type& original_value, const value_type& message) const;
 };
 
 struct postprocess_request : public details::converter<postprocess_request, slots::postprocess::v0::modify::CallRequest, std::string>
@@ -97,7 +97,7 @@ struct postprocess_request : public details::converter<postprocess_request, slot
 
 struct postprocess_response : public details::converter<postprocess_response, slots::postprocess::v0::modify::CallResponse, std::string>
 {
-    native_value_type operator()([[maybe_unused]] native_value_type& original_value, const value_type& message) const;
+    native_value_type operator()([[maybe_unused]] const native_value_type& original_value, const value_type& message) const;
 };
 
 struct infill_generate_request : public details::converter<infill_generate_request, slots::infill::v0::generate::CallRequest, Polygons>
diff --git a/src/plugins/converters.cpp b/src/plugins/converters.cpp
index d13c07d92e..e0e9c27a3b 100644
--- a/src/plugins/converters.cpp
+++ b/src/plugins/converters.cpp
@@ -125,7 +125,7 @@ simplify_request::value_type
 }
 
 simplify_response::native_value_type
-    simplify_response::operator()([[maybe_unused]] simplify_response::native_value_type& original_value, const simplify_response::value_type& message) const
+    simplify_response::operator()([[maybe_unused]] const simplify_response::native_value_type& original_value, const simplify_response::value_type& message) const
 {
     native_value_type poly{};
     for (const auto& paths : message.polygons().polygons())
@@ -158,7 +158,7 @@ postprocess_request::value_type postprocess_request::operator()(const postproces
 }
 
 postprocess_response::native_value_type
-    postprocess_response::operator()([[maybe_unused]] postprocess_response::native_value_type& original_value, const postprocess_response::value_type& message) const
+    postprocess_response::operator()([[maybe_unused]] const postprocess_response::native_value_type& original_value, const postprocess_response::value_type& message) const
 {
     return message.gcode_word();
 }
diff --git a/src/settings/PathConfigStorage.cpp b/src/settings/PathConfigStorage.cpp
index e32e9afb15..2f9dd2acea 100644
--- a/src/settings/PathConfigStorage.cpp
+++ b/src/settings/PathConfigStorage.cpp
@@ -138,7 +138,7 @@ PathConfigStorage::PathConfigStorage(const SliceDataStorage& storage, const Laye
             GCodePathConfig{ .type = PrintFeatureType::Support,
                              .line_width = static_cast<coord_t>(support_infill_train.settings.get<coord_t>("support_line_width") * support_infill_line_width_factor),
                              .layer_thickness = layer_thickness,
-                             .flow = -support_infill_train.settings.get<Ratio>("support_material_flow")
+                             .flow = support_infill_train.settings.get<Ratio>("support_material_flow")
                                    * ((layer_nr == 0) ? support_infill_train.settings.get<Ratio>("material_flow_layer_0") : Ratio(1.0)) * (combine_idx + 1),
                              .speed_derivatives = SpeedDerivatives{ .speed = support_infill_train.settings.get<Velocity>("speed_support_infill"),
                                                                     .acceleration = support_infill_train.settings.get<Acceleration>("acceleration_support_infill"),