diff --git a/src/libslic3r/ExtrusionRole.hpp b/src/libslic3r/ExtrusionRole.hpp
index a6426e0c6..5952d3fc5 100644
--- a/src/libslic3r/ExtrusionRole.hpp
+++ b/src/libslic3r/ExtrusionRole.hpp
@@ -83,6 +83,11 @@ struct ExtrusionRole : public ExtrusionRoleModifiers
     bool is_solid_infill() const { return this->is_infill() && this->ExtrusionRoleModifiers::has(ExtrusionRoleModifier::Solid); }
     bool is_external() const { return this->ExtrusionRoleModifiers::has(ExtrusionRoleModifier::External); }
     bool is_bridge() const { return this->ExtrusionRoleModifiers::has(ExtrusionRoleModifier::Bridge); }
+
+    bool is_support() const { return this->ExtrusionRoleModifiers::has(ExtrusionRoleModifier::Support); }
+    bool is_support_base() const { return this->is_support() && ! this->is_external(); }
+    bool is_support_interface() const { return this->is_support() && this->is_external(); }
+    bool is_mixed() const { return this->ExtrusionRoleModifiers::has(ExtrusionRoleModifier::Mixed); }
 };
 
 // Special flags describing loop
diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index d6d47cf71..07209c8d1 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -2246,29 +2246,24 @@ void GCode::process_layer_single_object(
     if (! print_wipe_extrusions && layer_to_print.support_layer != nullptr)
         if (const SupportLayer &support_layer = *layer_to_print.support_layer; ! support_layer.support_fills.entities.empty()) {
             ExtrusionRole   role               = support_layer.support_fills.role();
-            bool            has_support        = role == ExtrusionRole::Mixed || role == ExtrusionRole::SupportMaterial;
-            bool            has_interface      = role == ExtrusionRole::Mixed || role == ExtrusionRole::SupportMaterialInterface;
+            bool            has_support        = role.is_mixed() || role.is_support_base();
+            bool            has_interface      = role.is_mixed() || role.is_support_interface();
             // Extruder ID of the support base. -1 if "don't care".
             unsigned int    support_extruder   = print_object.config().support_material_extruder.value - 1;
             // Shall the support be printed with the active extruder, preferably with non-soluble, to avoid tool changes?
-            bool            support_dontcare   = print_object.config().support_material_extruder.value == 0;
+            bool            support_dontcare   = support_extruder == std::numeric_limits<unsigned int>::max();
             // Extruder ID of the support interface. -1 if "don't care".
             unsigned int    interface_extruder = print_object.config().support_material_interface_extruder.value - 1;
             // Shall the support interface be printed with the active extruder, preferably with non-soluble, to avoid tool changes?
-            bool            interface_dontcare = print_object.config().support_material_interface_extruder.value == 0;
+            bool            interface_dontcare = interface_extruder == std::numeric_limits<unsigned int>::max();
             if (support_dontcare || interface_dontcare) {
                 // Some support will be printed with "don't care" material, preferably non-soluble.
                 // Is the current extruder assigned a soluble filament?
-                unsigned int dontcare_extruder = layer_tools.extruders.front();
-                if (print.config().filament_soluble.get_at(dontcare_extruder)) {
-                    // The last extruder printed on the previous layer extrudes soluble filament.
-                    // Try to find a non-soluble extruder on the same layer.
-                    for (unsigned int extruder_id : layer_tools.extruders)
-                        if (! print.config().filament_soluble.get_at(extruder_id)) {
-                            dontcare_extruder = extruder_id;
-                            break;
-                        }
-                }
+                auto it_nonsoluble = std::find_if(layer_tools.extruders.begin(), layer_tools.extruders.end(), 
+                    [&soluble = std::as_const(print.config().filament_soluble)](unsigned int extruder_id) { return ! soluble.get_at(extruder_id); });
+                // There should be a non-soluble extruder available.
+                assert(it_nonsoluble != layer_tools.extruders.end());
+                unsigned int dontcare_extruder = it_nonsoluble == layer_tools.extruders.end() ? layer_tools.extruders.front() : *it_nonsoluble;
                 if (support_dontcare)
                     support_extruder = dontcare_extruder;
                 if (interface_dontcare)
@@ -2282,7 +2277,7 @@ void GCode::process_layer_single_object(
                 m_object_layer_over_raft = false;
                 gcode += this->extrude_support(
                     // support_extrusion_role is ExtrusionRole::SupportMaterial, ExtrusionRole::SupportMaterialInterface or ExtrusionRole::Mixed for all extrusion paths.
-                    support_layer.support_fills.chained_path_from(m_last_pos, has_support ? (has_interface ? ExtrusionRole::Mixed : ExtrusionRole::SupportMaterial) : ExtrusionRole::SupportMaterialInterface));
+                    support_layer.support_fills.chained_path_from(m_last_pos, extrude_support ? (extrude_interface ? ExtrusionRole::Mixed : ExtrusionRole::SupportMaterial) : ExtrusionRole::SupportMaterialInterface));
             }
         }