diff --git a/Tests/test_file_wmf.py b/Tests/test_file_wmf.py
index 64a78f400..bdfca80de 100644
--- a/Tests/test_file_wmf.py
+++ b/Tests/test_file_wmf.py
@@ -1,9 +1,21 @@
 from helper import unittest, PillowTestCase
 from PIL import Image
+from io import BytesIO
 
 
 class TestFileWmf(PillowTestCase):
 
+    def as_png(self, im):
+        # Pass the image through PNG save/load
+        out = BytesIO()
+        im.save(out, "PNG")
+        test_bytes = out.tell()
+        out.seek(0)
+        im = Image.open(out)
+        im.bytes = test_bytes  # for testing only
+        im.load()
+        return im
+
     def test_load_raw(self):
 
         # Test basic EMF open and rendering
@@ -14,7 +26,7 @@ class TestFileWmf(PillowTestCase):
             # Compare to reference rendering
             imref = Image.open('Tests/images/drawing_emf_ref.png')
             imref.load()
-            self.assert_image_equal(im, imref)
+            self.assert_image_equal(self.as_png(im), imref)
 
         # Test basic WMF open and rendering
         im = Image.open('Tests/images/drawing.wmf')
@@ -24,7 +36,7 @@ class TestFileWmf(PillowTestCase):
             # Compare to reference rendering
             imref = Image.open('Tests/images/drawing_wmf_ref.png')
             imref.load()
-            self.assert_image_equal(im, imref)
+            self.assert_image_equal(self.as_png(im), imref)
 
 
 if __name__ == '__main__':