diff --git a/osmclient/scripts/osm.py b/osmclient/scripts/osm.py
index 6d7a83446775a97ac91b62ecd0ae435ac7de1da4..5d331838ee462a23134561cf6185153064c1f4d1 100755
--- a/osmclient/scripts/osm.py
+++ b/osmclient/scripts/osm.py
@@ -369,6 +369,9 @@ def cli():
         )
     except ClientException as exc:
         print("ERROR: {}".format(exc))
+        print(
+            'Maybe "--hostname" option or OSM_HOSTNAME environment variable needs to be specified'
+        )
     except (FileNotFoundError, PermissionError) as exc:
         print("Cannot open file: {}".format(exc))
     except yaml.YAMLError as exc: