diff --git a/av98.py b/av98.py
index 94ad753..aa21650 100755
--- a/av98.py
+++ b/av98.py
@@ -282,10 +282,14 @@ Slow internet connection?  Use 'set timeout' to be more patient.""")
             new_gi = GeminiItem(gi.host, gi.port, mime, None)
             self._go_to_gi(new_gi)
             return
-        # Not found
+        # Error
         elif status.startswith("4") or status.startswith("5"):
             print("Error: %s" % mime)
             return
+        # Client cert
+        elif status.startswith("6"):
+            print("Client certificates not supported.")
+            return
 
         # If we're still here, this is a success and there's a response body