diff --git a/swh/lister/gnu/tree.py b/swh/lister/gnu/tree.py
--- a/swh/lister/gnu/tree.py
+++ b/swh/lister/gnu/tree.py
@@ -288,13 +288,11 @@
         Version detected
 
     Example:
-        For uri = https://ftp.gnu.org/gnu/8sync/8sync-0.2.0.tar.gz
-
+        >>> uri = 'https://ftp.gnu.org/gnu/8sync/8sync-0.2.0.tar.gz'
         >>> get_version(uri)
         '0.2.0'
 
-        For uri = 8sync-0.3.0.tar.gz
-
+        >>> uri = '8sync-0.3.0.tar.gz'
         >>> get_version(uri)
         '0.3.0'
 
diff --git a/swh/lister/utils.py b/swh/lister/utils.py
--- a/swh/lister/utils.py
+++ b/swh/lister/utils.py
@@ -9,13 +9,13 @@
     """Split `total_pages` into mostly `nb_pages` ranges. In some cases, the last range can
     have one more element.
 
-    >>> split_range(19, 10)
+    >>> list(split_range(19, 10))
     [(0, 9), (10, 19)]
 
-    >>> split_range(20, 3)
+    >>> list(split_range(20, 3))
     [(0, 2), (3, 5), (6, 8), (9, 11), (12, 14), (15, 17), (18, 20)]
 
-    >>> split_range(21, 3)
+    >>> list(split_range(21, 3))
     [(0, 2), (3, 5), (6, 8), (9, 11), (12, 14), (15, 17), (18, 21)]
 
     """
diff --git a/tox.ini b/tox.ini
--- a/tox.ini
+++ b/tox.ini
@@ -12,6 +12,7 @@
 commands =
   pytest \
   !dev: --cov={envsitepackagesdir}/swh/lister/ --cov-branch \
+        --doctest-modules \
          {envsitepackagesdir}/swh/lister/ {posargs}
 
 [testenv:black]