diff --git a/src/prune_theorems.c b/src/prune_theorems.c
index 4c4df1f..b8230d5 100644
--- a/src/prune_theorems.c
+++ b/src/prune_theorems.c
@@ -410,8 +410,12 @@ prune_theorems (const System sys)
 	    }
 	}
 
-      // To be on the safe side, we currently limit the encryption level. This is not a problem for known attacks, but should be addressed more carefully at some point.
+      // To be on the safe side, we currently limit the encryption level. 
       /**
+       * This is not a problem for known attacks, but should be addressed more
+       * carefully at some point.  If there are variables that can contain
+       * encryptions, this is maybe not correct: make proof!
+       *
        * @todo Fix untyped variables reasoning
        */
       if (term_encryption_level (b->term) > max_encryption_level)