diff --git a/src/do_name.c b/src/do_name.c
index 3aa6c8fb2..d23f76ef9 100644
--- a/src/do_name.c
+++ b/src/do_name.c
@@ -2291,6 +2291,7 @@ obj_pmname(struct obj *obj)
 
         return pmname(&mons[mndx], mgend);
     }
+    impossible("obj_pmname otyp:%i,corpsenm:%i", obj->otyp, obj->corpsenm);
     return "two-legged glorkum-seeker";
 }
 
diff --git a/src/objnam.c b/src/objnam.c
index 08406c627..af873e9be 100644
--- a/src/objnam.c
+++ b/src/objnam.c
@@ -271,6 +271,7 @@ safe_typename(int otyp)
         || !OBJ_NAME(objects[otyp])) {
         res = nextobuf();
         Sprintf(res, "glorkum[%d]", otyp);
+        impossible("safe_typename: %s", res);
     } else {
         /* force it to be treated as fully discovered */
         save_nameknown = objects[otyp].oc_name_known;
@@ -834,6 +835,7 @@ xname_flags(
     }
     default:
         Sprintf(buf, "glorkum %d %d %d", obj->oclass, typ, obj->spe);
+        impossible("xname_flags: %s", buf);
         break;
     }
     if (pluralize) {