diff --git a/xs/src/libslic3r/Model.cpp b/xs/src/libslic3r/Model.cpp
index 97f695e6aa..5372292568 100644
--- a/xs/src/libslic3r/Model.cpp
+++ b/xs/src/libslic3r/Model.cpp
@@ -1305,27 +1305,24 @@ TransformationMatrix ModelInstance::get_trafo_matrix(bool dont_translate) const
 
 BoundingBoxf3 ModelInstance::transform_bounding_box(const BoundingBoxf3 &bbox, bool dont_translate) const
 {
-    TransformationMatrix
-    Pointf3 pts[4] = {
-        bbox.min,
-        bbox.max,
-        Pointf3(bbox.min.x, bbox.max.y, bbox.min.z),
-        Pointf3(bbox.max.x, bbox.min.y, bbox.max.z)
+    TransformationMatrix trafo = this->get_trafo_matrix(dont_translate);
+    Pointf3 Poi_min = bbox.min;
+    Pointf3 Poi_max = bbox.max;
+
+    // all 8 corner points needed because the transformation could be anything
+    Pointf3 pts[8] = {
+        Pointf3(Poi_min.x, Poi_min.y, Poi_min.z),
+        Pointf3(Poi_min.x, Poi_min.y, Poi_max.z),
+        Pointf3(Poi_min.x, Poi_max.y, Poi_min.z),
+        Pointf3(Poi_min.x, Poi_max.y, Poi_max.z),
+        Pointf3(Poi_max.x, Poi_min.y, Poi_min.z),
+        Pointf3(Poi_max.x, Poi_min.y, Poi_max.z),
+        Pointf3(Poi_max.x, Poi_max.y, Poi_min.z),
+        Pointf3(Poi_max.x, Poi_max.y, Poi_max.z)
     };
     BoundingBoxf3 out;
-    for (int i = 0; i < 4; ++ i) {
-        Pointf3 &v = pts[i];
-        double xold = v.x;
-        double yold = v.y;
-        // Rotation around z axis.
-        v.x = float(c * xold - s * yold);
-        v.y = float(s * xold + c * yold);
-        v.scale(this->scaling_factor);
-        if (!dont_translate) {
-            v.x += this->offset.x;
-            v.y += this->offset.y;
-        }
-        out.merge(v);
+    for (int i = 0; i < 8; ++ i) {
+        out.merge(trafo.transform(pts[i]));
     }
     return out;
 }
diff --git a/xs/src/libslic3r/TransformationMatrix.cpp b/xs/src/libslic3r/TransformationMatrix.cpp
index cca9b3fecd..b4aa5f6038 100644
--- a/xs/src/libslic3r/TransformationMatrix.cpp
+++ b/xs/src/libslic3r/TransformationMatrix.cpp
@@ -155,6 +155,15 @@ TransformationMatrix TransformationMatrix::multiplyRight(const TransformationMat
     return multiply(*this, right);
 }
 
+Pointf3 TransformationMatrix::transform(const Pointf3 &point, coordf_t w) const
+{
+    Pointf3 out;
+    out.x = this->m00 * point.x + this->m01 * point.y + this->m02 * point.z + this->m03 * w;
+    out.y = this->m10 * point.x + this->m11 * point.y + this->m12 * point.z + this->m13 * w;
+    out.z = this->m20 * point.x + this->m21 * point.y + this->m22 * point.z + this->m23 * w;
+    return out;
+}
+
 TransformationMatrix TransformationMatrix::multiply(const TransformationMatrix &left, const TransformationMatrix &right)
 {
     TransformationMatrix trafo;
diff --git a/xs/src/libslic3r/TransformationMatrix.hpp b/xs/src/libslic3r/TransformationMatrix.hpp
index a6b6bfa76f..ef0e3422a2 100644
--- a/xs/src/libslic3r/TransformationMatrix.hpp
+++ b/xs/src/libslic3r/TransformationMatrix.hpp
@@ -77,6 +77,9 @@ class TransformationMatrix
     /// multiplies the parameter-matrix from the right (out=this*right)
     TransformationMatrix multiplyRight(const TransformationMatrix &right) const;
 
+    /// multiplies the Point from the right (out=this*right)
+    Pointf3 transform(const Pointf3 &point, coordf_t w = 1.0) const;
+
     /// generates an eye matrix.
     static TransformationMatrix mat_eye();