diff --git a/docs/commands/workflow_test_on_invocation.rst b/docs/commands/workflow_test_on_invocation.rst
index 14e0c5ef5..f8108f104 100644
--- a/docs/commands/workflow_test_on_invocation.rst
+++ b/docs/commands/workflow_test_on_invocation.rst
@@ -8,7 +8,7 @@ This section is auto-generated from the help text for the planemo command
 
 **Usage**::
 
-    planemo workflow_test_on_invocation [OPTIONS] TEST DEFINITION
+    planemo workflow_test_on_invocation [OPTIONS] TEST DEFINITION INVOCATION
 
 **Help**
 
diff --git a/planemo/commands/cmd_workflow_test_on_invocation.py b/planemo/commands/cmd_workflow_test_on_invocation.py
index adf6bca19..4384ae6da 100644
--- a/planemo/commands/cmd_workflow_test_on_invocation.py
+++ b/planemo/commands/cmd_workflow_test_on_invocation.py
@@ -14,17 +14,17 @@
 
 @click.command("workflow_test_on_invocation")
 @options.optional_tools_arg(multiple=False, allow_uris=False, metavar="TEST DEFINITION")
-@options.required_workflow_arg()
+@options.required_invocation_id_arg()
 @options.galaxy_url_option(required=True)
 @options.galaxy_user_key_option(required=True)
 @options.test_index_option()
 @options.test_output_options()
 @command_function
-def cli(ctx, path, workflow_identifier, test_index, **kwds):
+def cli(ctx, path, invocation_id, test_index, **kwds):
     """Run defined tests against existing workflow invocation."""
     with engine_context(ctx, engine="external_galaxy", **kwds) as engine, engine.ensure_runnables_served([]) as config:
         user_gi = config.user_gi
-        invocation = user_gi.invocations.show_invocation(workflow_identifier)
+        invocation = user_gi.invocations.show_invocation(invocation_id)
         runnable = for_runnable_identifier(ctx, f"{GALAXY_WORKFLOW_INSTANCE_PREFIX}{invocation['workflow_id']}", kwds)
         test_cases = definition_to_test_case(path, runnable)
         assert (
diff --git a/planemo/options.py b/planemo/options.py
index e387ddfe4..05f67b495 100644
--- a/planemo/options.py
+++ b/planemo/options.py
@@ -754,6 +754,14 @@ def required_workflow_arg():
     )
 
 
+def required_invocation_id_arg():
+    return click.argument(
+        "invocation_id",
+        metavar="INVOCATION ID",
+        type=str,
+    )
+
+
 def split_job_and_test():
     return click.option(
         "--split_test/--no_split_test", default=False, help="Write workflow job and test definitions to separate files."