diff --git a/skimage/io/_plugins/pil_plugin.py b/skimage/io/_plugins/pil_plugin.py
index 6fecbc2a..f7c10789 100644
--- a/skimage/io/_plugins/pil_plugin.py
+++ b/skimage/io/_plugins/pil_plugin.py
@@ -114,6 +114,9 @@ def pil_to_ndarray(im, dtype=None, img_num=None):
         frames.append(frame)
         i += 1
 
+        if img_num is not None:
+            break
+
     if hasattr(im, 'fp') and im.fp:
         im.fp.close()
 
diff --git a/skimage/io/collection.py b/skimage/io/collection.py
index 8812740e..bf8c58da 100644
--- a/skimage/io/collection.py
+++ b/skimage/io/collection.py
@@ -254,7 +254,7 @@ class ImageCollection(object):
                 kwargs = self.load_func_kwargs
                 if self._frame_index:
                     fname, img_num = self._frame_index[n]
-                    if img_num > 0:
+                    if img_num is not None:
                         self.data[idx] = self.load_func(fname, img_num=img_num,
                                                         **kwargs)
                     else: