diff --git a/skimage/restoration/tests/test_denoise.py b/skimage/restoration/tests/test_denoise.py
index 46cb05d0ef7..019a51c9f1c 100644
--- a/skimage/restoration/tests/test_denoise.py
+++ b/skimage/restoration/tests/test_denoise.py
@@ -4,6 +4,7 @@
 from skimage import restoration, data, color, img_as_float, measure
 from skimage._shared._warnings import expected_warnings
 from skimage.measure import compare_psnr
+from skimage.restoration._denoise import _wavelet_threshold
 
 np.random.seed(1234)