diff --git a/mollom.module b/mollom.module
index ebb1e13..ada2ab2 100644
--- a/mollom.module
+++ b/mollom.module
@@ -1656,8 +1656,15 @@ function mollom_validate_analysis(&$form, &$form_state) {
 
       case MOLLOM_ANALYSIS_UNKNOWN:
       default:
-        // If we end up here, something went totally wrong.
-        _mollom_fallback();
+        // If we end up here, Mollom responded with an unknown 'spam' value.
+        // Normally, this should not happen, but if it does, log it. As there
+        // could be multiple reasons for this, it is not safe to trigger the
+        // fallback mode.
+        _mollom_watchdog(array(
+          'Unknown: %teaser' => array('%teaser' => $teaser),
+          'Data:<pre>@data</pre>' => array('@data' => $data),
+          'Result:<pre>@result</pre>' => array('@result' => $result),
+        ));
         break;
     }
   }