diff --git a/imagetagger/imagetagger/annotations/models.py b/imagetagger/imagetagger/annotations/models.py
index d1b2421c..20ae86a9 100644
--- a/imagetagger/imagetagger/annotations/models.py
+++ b/imagetagger/imagetagger/annotations/models.py
@@ -137,8 +137,8 @@ def center(self):
                 AnnotationType.VECTOR_TYPE.BOUNDING_BOX,
                 AnnotationType.VECTOR_TYPE.LINE,
                 AnnotationType.VECTOR_TYPE.POLYGON):
-            yc = self.vector['y1'] + (self.height / 2)
-            xc = self.vector['x1'] + (self.width / 2)
+            yc = self.min_y + (self.height / 2)
+            xc = self.min_x + (self.width / 2)
         elif self.annotation_type.vector_type is AnnotationType.VECTOR_TYPE.POINT:
             yc = self.vector['y1']
             xc = self.vector['x1']