diff --git a/doc/source/index.rst b/doc/source/index.rst
index 9f00c10..0262d63 100644
--- a/doc/source/index.rst
+++ b/doc/source/index.rst
@@ -23,6 +23,8 @@ API Documentation
    api/excutils
    api/fileutils
    api/fixture
+   api/fnmatch
+   api/imageutils
    api/importutils
    api/netutils
    api/reflection
diff --git a/oslo_utils/fnmatch.py b/oslo_utils/fnmatch.py
index 62f9553..9b85da6 100644
--- a/oslo_utils/fnmatch.py
+++ b/oslo_utils/fnmatch.py
@@ -15,6 +15,8 @@
 Standard library fnmatch in Python versions <= 2.7.9 has thread safe
 issue, this module is created for such case. see:
 https://bugs.python.org/issue23191
+
+.. versionadded:: 3.3
 """
 
 from __future__ import absolute_import
diff --git a/oslo_utils/imageutils.py b/oslo_utils/imageutils.py
index b829abd..245a384 100644
--- a/oslo_utils/imageutils.py
+++ b/oslo_utils/imageutils.py
@@ -17,6 +17,8 @@
 
 """
 Helper methods to deal with images.
+
+.. versionadded:: 3.1
 """
 
 import re
@@ -26,6 +28,12 @@ from oslo_utils import strutils
 
 
 class QemuImgInfo(object):
+    """Parse Qemu image information from command `qemu-img info`'s output.
+
+    The instance of :class:`QemuImgInfo` has properties: `image`,
+    `backing_file`, `file_format`, `virtual_size`, `cluster_size`,
+    `disk_size`, `snapshots` and `encrypted`.
+    """
     BACKING_FILE_RE = re.compile((r"^(.*?)\s*\(actual\s+path\s*:"
                                   r"\s+(.*?)\)\s*$"), re.I)
     TOP_LEVEL_RE = re.compile(r"^([\w\d\s\_\-]+):(.*)$")