diff --git a/setup.cfg b/setup.cfg
index 8e642ee95db791973b1e8da9c868bc6f15671111..9e3f10d0202a499366a41c3356c559653c55ae50 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -39,3 +39,6 @@ per-file-ignores = __init__.py:F401
 [options.entry_points]
 console_scripts =
   caosdb-crawler = caoscrawler.crawl:main
+
+[options.extras_require]
+h5-crawler = h5py >= 3.8
diff --git a/src/caoscrawler/hdf5_converter.py b/src/caoscrawler/hdf5_converter.py
new file mode 100644
index 0000000000000000000000000000000000000000..1262aa5572f53b92ede0d531bc35a2a93efd69b8
--- /dev/null
+++ b/src/caoscrawler/hdf5_converter.py
@@ -0,0 +1,27 @@
+#
+# This file is a part of the CaosDB Project.
+#
+# Copyright (C) 2023 IndiScale GmbH <info@indiscale.com>
+# Copyright (C) 2023 Florian Spreckelsen <f.spreckelsen@indiscale.com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program. If not, see <https://www.gnu.org/licenses/>.
+#
+
+try:
+    import h5py
+except ModuleNotFoundError:
+    raise ModuleNotFoundError(
+        "Couldn't find module h5py. Did you install the crawler package with "
+        "its optional `h5-crawler` dependency?"
+    )