diff --git a/lib/Mnemosyne/Webhook.pm b/lib/Mnemosyne/Webhook.pm
index f2e7767..a48fad1 100644
--- a/lib/Mnemosyne/Webhook.pm
+++ b/lib/Mnemosyne/Webhook.pm
@@ -34,8 +34,11 @@ sub handle_update {
 
     warn "DBG full_update: " . encode_json($update) . "\n";
 
-    my $upd_type = exists $update->{message}       ? 'message'
-                 : exists $update->{callback_query} ? 'callback_query'
+    # callback_query is checked first: Telegram occasionally sends a stub
+    # top-level "message" key alongside callback_query updates, so existence
+    # of "message" alone is not a reliable discriminator.
+    my $upd_type = exists $update->{callback_query} ? 'callback_query'
+                 : exists $update->{message}         ? 'message'
                  : 'unknown';
     warn "DBG update type=$upd_type chat=$chat_id\n";