diff --git a/doc/source/user_guide/numpy_images.txt b/doc/source/user_guide/numpy_images.txt
index f4b3cf42..00f49bbb 100644
--- a/doc/source/user_guide/numpy_images.txt
+++ b/doc/source/user_guide/numpy_images.txt
@@ -77,7 +77,7 @@ disk: ::
     >>> nrows, ncols = camera.shape
     >>> row, col = np.ogrid[:nrows, :ncols]
     >>> cnt_row, cnt_col = nrows / 2, ncols / 2
-    >>> outer_disk_mask = ((row - cnt_row)**2 + (col - cnt_col)**2 <
+    >>> outer_disk_mask = ((row - cnt_row)**2 + (col - cnt_col)**2 >
     ...                    (nrows / 2)**2)
     >>> camera[outer_disk_mask] = 0