diff --git a/swh/dataset/cli.py b/swh/dataset/cli.py
index 55ac9ab..ac7981d 100644
--- a/swh/dataset/cli.py
+++ b/swh/dataset/cli.py
@@ -1,57 +1,63 @@
 # Copyright (C) 2020 The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
+# WARNING: do not import unnecessary things here to keep cli startup time under
+# control
 import click
-import uuid
 
-from swh.core import config
 from swh.core.cli import CONTEXT_SETTINGS
-from swh.dataset.graph import export_edges, sort_graph_nodes
 
 
 @click.group(name="dataset", context_settings=CONTEXT_SETTINGS)
 @click.option(
     "--config-file",
     "-C",
     default=None,
     type=click.Path(exists=True, dir_okay=False),
     help="Configuration file.",
 )
 @click.pass_context
 def cli(ctx, config_file):
     """Software Heritage Dataset Tools"""
-    ctx.ensure_object(dict)
+    from swh.core import config
 
+    ctx.ensure_object(dict)
     conf = config.read(config_file)
     ctx.obj["config"] = conf
 
 
 @cli.group("graph")
 @click.pass_context
 def graph(ctx):
     """Manage graph edges export"""
     pass
 
 
 @graph.command("export")
 @click.argument("export-path", type=click.Path())
 @click.option("--export-id", "-e", help="Unique ID of the export run.")
 @click.option("--processes", "-p", default=1, help="Number of parallel processes")
 @click.pass_context
 def export_graph(ctx, export_path, export_id, processes):
     """Export the Software Heritage graph as an edge dataset."""
+    import uuid
+
     config = ctx.obj["config"]
     if not export_id:
         export_id = str(uuid.uuid4())
 
+    from swh.dataset.graph import export_edges
+
     export_edges(config, export_path, export_id, processes)
 
 
 @graph.command("sort")
 @click.argument("export-path", type=click.Path())
 @click.pass_context
 def sort_graph(ctx, export_path):
     config = ctx.obj["config"]
+    from swh.dataset.graph import sort_graph_nodes
+
     sort_graph_nodes(export_path, config)