diff --git a/svgelements/svgelements.py b/svgelements/svgelements.py
index 1fd0eced..34c797ec 100644
--- a/svgelements/svgelements.py
+++ b/svgelements/svgelements.py
@@ -7584,33 +7584,18 @@ def union_bbox(elements, transformed=True, with_stroke=False):
         :param with_stroke: should the stroke-width be included in the bounds of the elements
         :return: union of all bounding boxes of elements within the iterable.
         """
-        boundary_points = []
+        boxes = []
         for e in elements:
-            if not hasattr(e, "bbox"):
+            if not hasattr(e, "bbox") or isinstance(e, (Group, Use)):
                 continue
-            box = e.bbox(transformed=False, with_stroke=with_stroke)
+            box = e.bbox(transformed=transformed, with_stroke=with_stroke)
             if box is None:
                 continue
-            top_left = (box[0], box[1])
-            top_right = (box[2], box[1])
-            bottom_left = (box[0], box[3])
-            bottom_right = (box[2], box[3])
-            if transformed:
-                top_left = e.transform.point_in_matrix_space(top_left)
-                top_right = e.transform.point_in_matrix_space(top_right)
-                bottom_left = e.transform.point_in_matrix_space(bottom_left)
-                bottom_right = e.transform.point_in_matrix_space(bottom_right)
-            boundary_points.append(top_left)
-            boundary_points.append(top_right)
-            boundary_points.append(bottom_left)
-            boundary_points.append(bottom_right)
-        if len(boundary_points) == 0:
+            boxes.append(box)
+        if len(boxes) == 0:
             return None
-        xmin = min([e[0] for e in boundary_points])
-        ymin = min([e[1] for e in boundary_points])
-        xmax = max([e[0] for e in boundary_points])
-        ymax = max([e[1] for e in boundary_points])
-        return xmin, ymin, xmax, ymax
+        (xmins, ymins, xmaxs, ymaxs) = zip(*boxes)
+        return (min(xmins), min(ymins), max(xmaxs), max(ymaxs))
 
     def bbox(self, transformed=True, with_stroke=False):
         """
diff --git a/test/test_bbox.py b/test/test_bbox.py
index 292b8812..92f2061b 100644
--- a/test/test_bbox.py
+++ b/test/test_bbox.py
@@ -275,6 +275,58 @@ def test_bbox_subpath_stroke(self):
             61 + (5. / 2.)
         ))
 
+    def test_bbox_rotated_circle(self):
+        # Rotation of circle must not affect it's bounding box
+        c = Circle(cx=0, cy=0, r=1, transform="rotate(45)")
+        (xmin, ymin, xmax, ymax) = c.bbox()
+        self.assertAlmostEqual(-1, xmin)
+        self.assertAlmostEqual(-1, ymin)
+        self.assertAlmostEqual( 1, xmax)
+        self.assertAlmostEqual( 1, ymax)
+
+    def test_bbox_svg_with_rotated_circle(self):
+        # Rotation of circle within group must not affect it's bounding box
+        q = io.StringIO(
+            u'''<?xml version="1.0" encoding="utf-8" ?>
+            <svg>
+              <circle cx="0" cy="0" r="1" transform="rotate(45)"/>
+            </svg>
+            '''
+        )
+        svg = SVG.parse(q)
+        (xmin, ymin, xmax, ymax) = svg.bbox()
+        self.assertAlmostEqual(-1, xmin)
+        self.assertAlmostEqual(-1, ymin)
+        self.assertAlmostEqual( 1, xmax)
+        self.assertAlmostEqual( 1, ymax)
+
+    def test_bbox_translated_circle(self):
+        c = Circle(cx=0, cy=0, r=1, transform="translate(-1,-1)")
+        (xmin, ymin, xmax, ymax) = c.bbox()
+        self.assertAlmostEqual(-2, xmin)
+        self.assertAlmostEqual(-2, ymin)
+        self.assertAlmostEqual( 0, xmax)
+        self.assertAlmostEqual( 0, ymax)
+
+    def test_bbox_svg_with_translated_group_with_circle(self):
+        # Translation of nested group must be applied correctly
+        q = io.StringIO(
+            u'''<?xml version="1.0" encoding="utf-8" ?>
+            <svg>
+              <g transform="translate(-1,-1)">
+                <circle cx="0" cy="0" r="1"/>
+              </g>
+            </svg>
+            '''
+        )
+        svg = SVG.parse(q)
+        (xmin, ymin, xmax, ymax) = svg.bbox()
+        self.assertAlmostEqual(-2, xmin)
+        self.assertAlmostEqual(-2, ymin)
+        self.assertAlmostEqual( 0, xmax)
+        self.assertAlmostEqual( 0, ymax)
+
+
     def test_issue_104(self):
         """Testing Issue 104 rotated bbox"""
         rect = Rect(10,10,10,10)