diff --git a/xs/src/libslic3r/GCode/ToolOrdering.hpp b/xs/src/libslic3r/GCode/ToolOrdering.hpp
index fe2c394c5..abf1aa6b2 100644
--- a/xs/src/libslic3r/GCode/ToolOrdering.hpp
+++ b/xs/src/libslic3r/GCode/ToolOrdering.hpp
@@ -53,14 +53,14 @@ public:
 
 	void 				clear() { m_layer_tools.clear(); }
 
-	// Get the first extruder printing the layer_tools, returns -1 if there is no layer printed.
+	// Get the first extruder printing, including the extruder priming areas, returns -1 if there is no layer printed.
 	unsigned int   		first_extruder() const { return m_first_printing_extruder; }
 
 	// Get the first extruder printing the layer_tools, returns -1 if there is no layer printed.
 	unsigned int   		last_extruder() const { return m_last_printing_extruder; }
 
 	// For a multi-material print, the printing extruders are ordered in the order they shall be primed.
-	std::vector<unsigned int> all_extruders() const { return m_all_printing_extruders; }
+	const std::vector<unsigned int>& all_extruders() const { return m_all_printing_extruders; }
 
 	// Find LayerTools with the closest print_z.
 	LayerTools&			tools_for_layer(coordf_t print_z);
diff --git a/xs/src/libslic3r/GCode/WipeTower.hpp b/xs/src/libslic3r/GCode/WipeTower.hpp
index c21c1710b..2c92e16e6 100644
--- a/xs/src/libslic3r/GCode/WipeTower.hpp
+++ b/xs/src/libslic3r/GCode/WipeTower.hpp
@@ -109,7 +109,7 @@ public:
 		// print_z of the first layer.
 		float 						first_layer_height, 
 		// Extruder indices, in the order to be primed. The last extruder will later print the wipe tower brim, print brim and the object.
-		std::vector<unsigned int> 	tools,
+		const std::vector<unsigned int> &tools,
 		// If true, the last priming are will be the same as the other priming areas, and the rest of the wipe will be performed inside the wipe tower.
 		// If false, the last priming are will be large enough to wipe the last extruder sufficiently.
 		bool 						last_wipe_inside_wipe_tower, 
diff --git a/xs/src/libslic3r/GCode/WipeTowerPrusaMM.cpp b/xs/src/libslic3r/GCode/WipeTowerPrusaMM.cpp
index 951d71075..b81a8b04b 100644
--- a/xs/src/libslic3r/GCode/WipeTowerPrusaMM.cpp
+++ b/xs/src/libslic3r/GCode/WipeTowerPrusaMM.cpp
@@ -368,7 +368,7 @@ WipeTower::ToolChangeResult WipeTowerPrusaMM::prime(
 	// print_z of the first layer.
 	float 						first_layer_height, 
 	// Extruder indices, in the order to be primed. The last extruder will later print the wipe tower brim, print brim and the object.
-	std::vector<unsigned int> 	tools,
+	const std::vector<unsigned int> &tools,
 	// If true, the last priming are will be the same as the other priming areas, and the rest of the wipe will be performed inside the wipe tower.
 	// If false, the last priming are will be large enough to wipe the last extruder sufficiently.
 	bool 						last_wipe_inside_wipe_tower, 
diff --git a/xs/src/libslic3r/GCode/WipeTowerPrusaMM.hpp b/xs/src/libslic3r/GCode/WipeTowerPrusaMM.hpp
index 15a96d367..b8c7ab31f 100644
--- a/xs/src/libslic3r/GCode/WipeTowerPrusaMM.hpp
+++ b/xs/src/libslic3r/GCode/WipeTowerPrusaMM.hpp
@@ -112,7 +112,7 @@ public:
 		// print_z of the first layer.
 		float 						first_layer_height, 
 		// Extruder indices, in the order to be primed. The last extruder will later print the wipe tower brim, print brim and the object.
-		std::vector<unsigned int> 	tools,
+		const std::vector<unsigned int> &tools,
 		// If true, the last priming are will be the same as the other priming areas, and the rest of the wipe will be performed inside the wipe tower.
 		// If false, the last priming are will be large enough to wipe the last extruder sufficiently.
 		bool 						last_wipe_inside_wipe_tower, 
diff --git a/xs/src/libslic3r/Print.cpp b/xs/src/libslic3r/Print.cpp
index 78ebf9294..c25e5de7d 100644
--- a/xs/src/libslic3r/Print.cpp
+++ b/xs/src/libslic3r/Print.cpp
@@ -974,7 +974,6 @@ void Print::_make_wipe_tower()
 
     // Let the ToolOrdering class know there will be initial priming extrusions at the start of the print.
     m_tool_ordering = ToolOrdering(*this, (unsigned int)-1, true);
-    unsigned int initial_extruder_id = m_tool_ordering.first_extruder();
     if (! m_tool_ordering.has_wipe_tower())
         // Don't generate any wipe tower.
         return;
@@ -983,7 +982,7 @@ void Print::_make_wipe_tower()
     WipeTowerPrusaMM wipe_tower(
         float(this->config.wipe_tower_x.value),     float(this->config.wipe_tower_y.value), 
         float(this->config.wipe_tower_width.value), float(this->config.wipe_tower_per_color_wipe.value),
-        initial_extruder_id);
+        m_tool_ordering.first_extruder());
     
     //wipe_tower.set_retract();
     //wipe_tower.set_zhop();
@@ -1006,7 +1005,8 @@ void Print::_make_wipe_tower()
 
     // Generate the wipe tower layers.
     m_wipe_tower_tool_changes.reserve(m_tool_ordering.layer_tools().size());
-    unsigned int current_extruder_id = initial_extruder_id;
+    // Set current_extruder_id to the last extruder primed.
+    unsigned int current_extruder_id = m_tool_ordering.all_extruders().back();
     for (const ToolOrdering::LayerTools &layer_tools : m_tool_ordering.layer_tools()) {
         if (! layer_tools.has_wipe_tower)
             // This is a support only layer, or the wipe tower does not reach to this height.
@@ -1021,7 +1021,11 @@ void Print::_make_wipe_tower()
             last_layer);
         std::vector<WipeTower::ToolChangeResult> tool_changes;
         for (unsigned int extruder_id : layer_tools.extruders)
-            if ((first_layer && extruder_id == initial_extruder_id) || extruder_id != current_extruder_id) {
+            // Call the wipe_tower.tool_change() at the first layer for the initial extruder 
+            // to extrude the wipe tower brim,
+            if ((first_layer && extruder_id == m_tool_ordering.all_extruders().back()) || 
+            // or when an extruder shall be switched.
+                extruder_id != current_extruder_id) {
                 tool_changes.emplace_back(wipe_tower.tool_change(extruder_id, extruder_id == layer_tools.extruders.back(), WipeTower::PURPOSE_EXTRUDE));
                 current_extruder_id = extruder_id;
             }