diff --git a/skimage/feature/template.py b/skimage/feature/template.py
index d06e82df..c9914b14 100644
--- a/skimage/feature/template.py
+++ b/skimage/feature/template.py
@@ -2,7 +2,7 @@ import numpy as np
 from scipy.signal import fftconvolve
 
 from skimage.util import pad
-from skimage._shared.utils impor assert_nD
+from skimage._shared.utils import assert_nD
 
 
 def _window_sum_2d(image, window_shape):
diff --git a/skimage/filter/lpi_filter.py b/skimage/filter/lpi_filter.py
index 1224abe7..88834b78 100644
--- a/skimage/filter/lpi_filter.py
+++ b/skimage/filter/lpi_filter.py
@@ -227,7 +227,10 @@ def wiener(data, impulse_response=None, filter_params={}, K=0.25,
 
     """
     assert_nD(data, 'data')
-    assert_nD(K, 'K')
+
+    if not isinstance(K, float):
+        assert_nD(K, 'K')
+
     if predefined_filter is None:
         filt = LPIFilter2D(impulse_response, **filter_params)
     else: