diff --git a/lib/matplotlib/transforms.py b/lib/matplotlib/transforms.py
index 51182616b8a0..3f435829d49f 100644
--- a/lib/matplotlib/transforms.py
+++ b/lib/matplotlib/transforms.py
@@ -697,10 +697,13 @@ def union(bboxes):
         """Return a `Bbox` that contains all of the given *bboxes*."""
         if not len(bboxes):
             raise ValueError("'bboxes' cannot be empty")
-        x0 = np.min([bbox.xmin for bbox in bboxes])
-        x1 = np.max([bbox.xmax for bbox in bboxes])
-        y0 = np.min([bbox.ymin for bbox in bboxes])
-        y1 = np.max([bbox.ymax for bbox in bboxes])
+        # needed for 1.14.4 < numpy_version < 1.15
+        # can remove once we are at numpy >= 1.15
+        with np.errstate(invalid='ignore'):
+            x0 = np.min([bbox.xmin for bbox in bboxes])
+            x1 = np.max([bbox.xmax for bbox in bboxes])
+            y0 = np.min([bbox.ymin for bbox in bboxes])
+            y1 = np.max([bbox.ymax for bbox in bboxes])
         return Bbox([[x0, y0], [x1, y1]])
 
     @staticmethod