diff --git a/src/stratis_cli/_actions/_introspect.py b/src/stratis_cli/_actions/_introspect.py
index ec010f9f0..6326c2362 100644
--- a/src/stratis_cli/_actions/_introspect.py
+++ b/src/stratis_cli/_actions/_introspect.py
@@ -14,7 +14,7 @@
       <arg name="key_desc" type="(bs)" direction="in" />
       <arg name="clevis_info" type="(b(ss))" direction="in" />
       <arg name="journal_size" type="(bt)" direction="in" />
-      <arg name="tag_size" type="(by)" direction="in" />
+      <arg name="tag_spec" type="(bs)" direction="in" />
       <arg name="result" type="(b(oao))" direction="out" />
       <arg name="return_code" type="q" direction="out" />
       <arg name="return_string" type="s" direction="out" />