diff --git a/skimage/morphology/binary.py b/skimage/morphology/binary.py
index 0b98ed6c..89ae8057 100644
--- a/skimage/morphology/binary.py
+++ b/skimage/morphology/binary.py
@@ -33,12 +33,11 @@ def binary_erosion(image, selem, out=None):
     selem_sum = np.sum(selem)
 
     if selem_sum <= 255:
-        binary = (image > 0).view(np.uint8)
         conv = np.empty_like(image, dtype=np.uint8)
     else:
-        binary = (image > 0).astype(np.intp)
         conv = np.empty_like(image, dtype=np.intp)
 
+    binary = (image > 0).view(np.uint8)
     ndimage.convolve(binary, selem, mode='constant', cval=1, output=conv)
 
     if out is None:
@@ -74,13 +73,13 @@ def binary_dilation(image, selem, out=None):
 
     """
     selem = (selem != 0)
+
     if np.sum(selem) <= 255:
-        binary = (image > 0).view(np.uint8)
         conv = np.empty_like(image, dtype=np.uint8)
     else:
-        binary = (image > 0).astype(np.intp)
         conv = np.empty_like(image, dtype=np.intp)
 
+    binary = (image > 0).view(np.uint8)
     ndimage.convolve(binary, selem, mode='constant', cval=0, output=conv)
 
     if out is None: