diff --git a/skimage/segmentation/slic_superpixels.py b/skimage/segmentation/slic_superpixels.py
index 08ea7126..be07fafe 100644
--- a/skimage/segmentation/slic_superpixels.py
+++ b/skimage/segmentation/slic_superpixels.py
@@ -27,7 +27,7 @@ def slic(image, n_segments=100, compactness=10., max_iter=10, sigma=None,
         infinity, superpixel shapes become square/cubic.
     max_iter : int, optional
         Maximum number of iterations of k-means.
-    sigma : float or (3,) array of floats, optional
+    sigma : float or (3,) array-like of floats, optional
         Width of Gaussian smoothing kernel for pre-processing for each
         dimension of the image. The same sigma is applied to each dimension in
         case of a scalar value. Zero means no smoothing.
@@ -104,7 +104,9 @@ def slic(image, n_segments=100, compactness=10., max_iter=10, sigma=None,
         image = image[..., np.newaxis]
 
     if not isinstance(sigma, coll.Iterable):
-        sigma = np.array([sigma, sigma, sigma])
+        sigma = np.array([sigma, sigma, sigma], float)
+    elif type(sigma) in [list, tuple]:
+        sigma = np.array(sigma, float)
     if (sigma > 0).any():
         sigma = list(sigma) + [0]
         image = ndimage.gaussian_filter(image, sigma)
diff --git a/skimage/segmentation/tests/test_slic.py b/skimage/segmentation/tests/test_slic.py
index 6d00716f..2a190de8 100644
--- a/skimage/segmentation/tests/test_slic.py
+++ b/skimage/segmentation/tests/test_slic.py
@@ -90,6 +90,17 @@ def test_gray_3d():
         assert_array_equal(seg[s], c)
 
 
+def test_list_sigma():
+    rnd = np.random.RandomState(0)
+    img = np.array([[1, 1, 1, 0, 0, 0],
+                    [0, 0, 0, 1, 1, 1]], np.float)
+    img += 0.1 * rnd.normal(size=img.shape)
+    result_sigma = np.array([[0, 0, 0, 1, 1, 1],
+                             [0, 0, 0, 1, 1, 1]], np.int)
+    seg_sigma = slic(img, n_segments=2, sigma=[1, 50, 1], multichannel=False)
+    assert_equal(seg_sigma, result_sigma)
+
+
 if __name__ == '__main__':
     from numpy import testing
     testing.run_module_suite()