diff --git a/skimage/feature/_daisy.py b/skimage/feature/_daisy.py
index 1a97de8f..3a55faf1 100644
--- a/skimage/feature/_daisy.py
+++ b/skimage/feature/_daisy.py
@@ -94,15 +94,15 @@ def daisy(img, step=4, radius=15, rings=3, histograms=8, orientations=8,
     '''
 
     # Validate image format.
-    if img.ndim > 2:
+    if img.ndim != 2:
         raise ValueError('Only grey-level images are supported.')
-    if img.dtype.kind != 'f':
-        img = img_as_float(img)
+
+    img = img_as_float(img)
 
     # Validate parameters.
     if sigmas is not None and ring_radii is not None \
             and len(sigmas) - 1 != len(ring_radii):
-        raise ValueError('len(sigmas)-1 != len(ring_radii)')
+        raise ValueError('`len(sigmas)-1 != len(ring_radii)`')
     if ring_radii is not None:
         rings = len(ring_radii)
         radius = ring_radii[-1]
diff --git a/skimage/feature/tests/test_daisy.py b/skimage/feature/tests/test_daisy.py
index 7f4e85d7..32a7a5df 100644
--- a/skimage/feature/tests/test_daisy.py
+++ b/skimage/feature/tests/test_daisy.py
@@ -45,8 +45,15 @@ def test_descs_shape():
     assert(descs.shape[1] == ceil((img.shape[1] - radius * 2) / float(step)))
 
 
+def test_daisy_sigmas_and_radii():
+    img = img_as_float(data.lena()[:64, :64].mean(axis=2))
+    sigmas = [1, 2, 3]
+    radii = [1, 2]
+    daisy(img, sigmas=sigmas, ring_radii=radii)
+
+
 def test_daisy_incompatible_sigmas_and_radii():
-    img = img_as_float(data.lena()[:128, :128].mean(axis=2))
+    img = img_as_float(data.lena()[:64, :64].mean(axis=2))
     sigmas = [1, 2]
     radii = [1, 2]
     assert_raises(ValueError, daisy, img, sigmas=sigmas, ring_radii=radii)