diff --git a/src/libslic3r/Fill/Fill.cpp b/src/libslic3r/Fill/Fill.cpp
index ab20bbddb..498abe89e 100644
--- a/src/libslic3r/Fill/Fill.cpp
+++ b/src/libslic3r/Fill/Fill.cpp
@@ -114,7 +114,7 @@ std::vector<SurfaceFill> group_fills(const Layer &layer)
 	        if (surface.surface_type == stInternalVoid)
 	        	has_internal_voids = true;
 	        else {
-		        FlowRole extrusion_role = (surface.surface_type == stTop) ? frTopSolidInfill : (surface.is_solid() ? frSolidInfill : frInfill);
+		        FlowRole extrusion_role = surface.is_top() ? frTopSolidInfill : (surface.is_solid() ? frSolidInfill : frInfill);
 		        bool     is_bridge 	    = layer.id() > 0 && surface.is_bridge();
 		        params.extruder 	 = layerm.region()->extruder(extrusion_role);
 		        params.pattern 		 = layerm.region()->config().fill_pattern.value;
@@ -132,7 +132,7 @@ std::vector<SurfaceFill> group_fills(const Layer &layer)
 		            is_bridge ?
 		                erBridgeInfill :
 		                (surface.is_solid() ?
-		                    ((surface.surface_type == stTop) ? erTopSolidInfill : erSolidInfill) :
+		                    (surface.is_top() ? erTopSolidInfill : erSolidInfill) :
 		                    erInternalInfill);
 		        params.bridge_angle = float(surface.bridge_angle);
 		        params.angle 		= float(Geometry::deg2rad(layerm.region()->config().fill_angle.value));
diff --git a/src/libslic3r/LayerRegion.cpp b/src/libslic3r/LayerRegion.cpp
index 67a1acb09..19907d6de 100644
--- a/src/libslic3r/LayerRegion.cpp
+++ b/src/libslic3r/LayerRegion.cpp
@@ -117,7 +117,7 @@ void LayerRegion::process_external_surfaces(const Layer *lower_layer, const Poly
         // Voids are sparse infills if infill rate is zero.
         Polygons voids;
         for (const Surface &surface : this->fill_surfaces.surfaces) {
-            if (surface.surface_type == stTop) {
+            if (surface.is_top()) {
                 // Collect the top surfaces, inflate them and trim them by the bottom surfaces.
                 // This gives the priority to bottom surfaces.
                 surfaces_append(top, offset_ex(surface.expolygon, margin, EXTERNAL_SURFACES_OFFSET_PARAMETERS), surface);
@@ -313,7 +313,7 @@ void LayerRegion::process_external_surfaces(const Layer *lower_layer, const Poly
                     s2.clear();
                 }
             }
-            if (s1.surface_type == stTop)
+            if (s1.is_top())
                 // Trim the top surfaces by the bottom surfaces. This gives the priority to the bottom surfaces.
                 polys = diff(polys, bottom_polygons);
             surfaces_append(
diff --git a/src/libslic3r/PrintObject.cpp b/src/libslic3r/PrintObject.cpp
index ed1a51e5d..5573f4ac3 100644
--- a/src/libslic3r/PrintObject.cpp
+++ b/src/libslic3r/PrintObject.cpp
@@ -817,11 +817,12 @@ void PrintObject::detect_surfaces_type()
                 m_layers[idx_layer]->m_regions[idx_region]->slices.surfaces = std::move(surfaces_new[idx_layer]);
         }
 
-        if (spiral_vase && num_layers > 1) {
-        	// Turn the last bottom layer infill to a top infill, so it will be extruded with a proper pattern.
-        	Surfaces &surfaces = m_layers[num_layers - 1]->m_regions[idx_region]->slices.surfaces;
-        	for (Surface &surface : surfaces)
-        		surface.surface_type = stTop;
+        if (spiral_vase) {
+        	if (num_layers > 1)
+	        	// Turn the last bottom layer infill to a top infill, so it will be extruded with a proper pattern.
+	        	m_layers[num_layers - 1]->m_regions[idx_region]->slices.set_type(stTop);
+	        for (size_t i = num_layers; i < m_layers.size(); ++ i)
+	        	m_layers[i]->m_regions[idx_region]->slices.set_type(stInternal);
         }
 
         BOOST_LOG_TRIVIAL(debug) << "Detecting solid surfaces for region " << idx_region << " - clipping in parallel - start";
diff --git a/src/libslic3r/SurfaceCollection.hpp b/src/libslic3r/SurfaceCollection.hpp
index b60105eb3..9f0324d20 100644
--- a/src/libslic3r/SurfaceCollection.hpp
+++ b/src/libslic3r/SurfaceCollection.hpp
@@ -34,6 +34,10 @@ public:
     void remove_type(const SurfaceType type);
     void remove_types(const SurfaceType *types, int ntypes);
     void filter_by_type(SurfaceType type, Polygons* polygons);
+    void set_type(SurfaceType type) {
+    	for (Surface &surface : this->surfaces)
+    		surface.surface_type = type;
+    }
 
     void clear() { surfaces.clear(); }
     bool empty() const { return surfaces.empty(); }