diff --git a/src/nix-env/nix-env.cc b/src/nix-env/nix-env.cc
index 9c78f01214..e0de2812ca 100644
--- a/src/nix-env/nix-env.cc
+++ b/src/nix-env/nix-env.cc
@@ -1062,7 +1062,7 @@ static void opQuery(Globals & globals,
             cout.flush();
 
         } catch (AssertionError & e) {
-            /* !!! hm, maybe we should give some sort of warning here? */
+            printMsg(lvlTalkative, format("skipping derivation named `%1%' which gives an assertion failure") % i->name);
         }
     }