diff --git a/skimage/measure/tests/test_regionprops.py b/skimage/measure/tests/test_regionprops.py
index 6c7f5d46..bd23d8b3 100644
--- a/skimage/measure/tests/test_regionprops.py
+++ b/skimage/measure/tests/test_regionprops.py
@@ -248,7 +248,7 @@ def test_perimeter():
     per = regionprops(SAMPLE, ['Perimeter'])[0]['Perimeter']
     assert_almost_equal(per, 59.2132034355964)
 
-    per = perimeter(SAMPLE, neighbourhood=8)
+    per = perimeter(SAMPLE.astype('double'), neighbourhood=8)
     assert_almost_equal(per, 43.1213203436)