diff --git a/contrib/check-py3-compat.py b/contrib/check-py3-compat.py
--- a/contrib/check-py3-compat.py
+++ b/contrib/check-py3-compat.py
@@ -51,9 +51,10 @@ def check_compat_py3(f):
         return
 
     # Try to import the module.
-    # For now we only support mercurial.* and hgext.* modules because figuring
-    # out module paths for things not in a package can be confusing.
-    if f.startswith(('hgext/', 'mercurial/')) and not f.endswith('__init__.py'):
+    # For now we only support modules in packages because figuring out module
+    # paths for things not in a package can be confusing.
+    if (f.startswith(('hgdemandimport/', 'hgext/', 'mercurial/'))
+        and not f.endswith('__init__.py')):
         assert f.endswith('.py')
         name = f.replace('/', '.')[:-3]
         try:
diff --git a/tests/test-check-help.t b/tests/test-check-help.t
--- a/tests/test-check-help.t
+++ b/tests/test-check-help.t
@@ -23,6 +23,6 @@
 Check if ":hg:`help TOPIC`" is valid:
 (use "xargs -n1 -t" to see which help commands are executed)
 
-  $ hg files 'glob:{hgext,mercurial}/**/*.py' | sed 's|\\|/|g' \
+  $ hg files 'glob:{hgdemandimport,hgext,mercurial}/**/*.py' | sed 's|\\|/|g' \
   > | xargs python "$TESTTMP/scanhelptopics.py" \
   > | xargs -n1 hg help > /dev/null
diff --git a/tests/test-check-pylint.t b/tests/test-check-pylint.t
--- a/tests/test-check-pylint.t
+++ b/tests/test-check-pylint.t
@@ -12,7 +12,7 @@ Current checks:
   $ touch $TESTTMP/fakerc
   $ pylint --rcfile=$TESTTMP/fakerc --disable=all \
   >   --enable=W0102 --reports=no \
-  >   mercurial hgext hgext3rd
+  >   mercurial hgdemandimport hgext hgext3rd
    (?)
   ------------------------------------ (?)
   Your code has been rated at 10.00/10 (?)