diff --git a/src/awx_plugins/credentials/conjur.py b/src/awx_plugins/credentials/conjur.py
index 86e54e1240..08ceb906d2 100644
--- a/src/awx_plugins/credentials/conjur.py
+++ b/src/awx_plugins/credentials/conjur.py
@@ -76,6 +76,7 @@
 def _is_base64(s: str) -> bool:
     """Check if a given string is base64-encoded.
 
+    :param s: String to check.
     :returns: Whether the string is base64-encoded or not.
     """
     try: