diff --git a/skimage/morphology/binary.py b/skimage/morphology/binary.py
index 216e3690..4244738f 100644
--- a/skimage/morphology/binary.py
+++ b/skimage/morphology/binary.py
@@ -1,4 +1,6 @@
-import warnings
+"""
+Binary morphological operations
+"""
 import numpy as np
 from scipy import ndimage
 from .misc import default_fallback
diff --git a/skimage/morphology/grey.py b/skimage/morphology/grey.py
index cd3dcaa8..e65e756b 100644
--- a/skimage/morphology/grey.py
+++ b/skimage/morphology/grey.py
@@ -1,4 +1,6 @@
-import warnings
+"""
+Grayscale morphological operations
+"""
 from skimage import img_as_ubyte
 from .misc import default_fallback