diff --git a/lbry/lbry/extras/daemon/comment_client.py b/lbry/lbry/extras/daemon/comment_client.py
index 7ded152a4..acbbc9297 100644
--- a/lbry/lbry/extras/daemon/comment_client.py
+++ b/lbry/lbry/extras/daemon/comment_client.py
@@ -19,19 +19,20 @@ def get_encoded_signature(signature):
 
 
 def is_comment_signed_by_channel(comment: dict, channel: Output):
-    try:
-        pieces = [
-            comment['signing_ts'].encode(),
-            channel.claim_hash,
-            comment['comment'].encode()
-        ]
-        return Output.is_signature_valid(
-            get_encoded_signature(comment['signature']),
-            sha256(b''.join(pieces)),
-            channel.claim.channel.public_key_bytes
-        )
-    except KeyError:
-        pass
+    if type(channel) is Output:
+        try:
+            pieces = [
+                comment['signing_ts'].encode(),
+                channel.claim_hash,
+                comment['comment'].encode()
+            ]
+            return Output.is_signature_valid(
+                get_encoded_signature(comment['signature']),
+                sha256(b''.join(pieces)),
+                channel.claim.channel.public_key_bytes
+            )
+        except KeyError:
+            pass
     return False