diff --git a/skimage/morphology/greyreconstruct.py b/skimage/morphology/greyreconstruct.py
index bce26d6b..ec7aa182 100644
--- a/skimage/morphology/greyreconstruct.py
+++ b/skimage/morphology/greyreconstruct.py
@@ -152,6 +152,9 @@ def reconstruction(seed, mask, method='dilation', selem=None, offset=None):
         pad_value = np.min(seed)
     elif method == 'erosion':
         pad_value = np.max(seed)
+    else:
+        raise ValueError("Reconstruction method can be one of 'erosion' "
+                         "or 'dilation'. Got '%s'." % method)
     images = np.ones(dims) * pad_value
     images[[0] + inside_slices] = seed
     images[[1] + inside_slices] = mask
diff --git a/skimage/morphology/tests/test_reconstruction.py b/skimage/morphology/tests/test_reconstruction.py
index f5678c08..df9ddf8f 100644
--- a/skimage/morphology/tests/test_reconstruction.py
+++ b/skimage/morphology/tests/test_reconstruction.py
@@ -97,6 +97,12 @@ def test_invalid_selem():
     reconstruction(seed, mask, selem=np.ones((3, 3)))
 
 
+def test_invalid_method():
+    seed = np.array([0, 8, 8, 8, 8, 8, 8, 8, 8, 0])
+    mask = np.array([0, 3, 6, 2, 1, 1, 1, 4, 2, 0])
+    assert_raises(ValueError, reconstruction, seed, mask, method='foo')
+
+
 if __name__ == '__main__':
     from numpy import testing
     testing.run_module_suite()