diff --git a/src/test/test_protover.c b/src/test/test_protover.c
index e7e17efe32..7bf1471ebd 100644
--- a/src/test/test_protover.c
+++ b/src/test/test_protover.c
@@ -283,23 +283,22 @@ test_protover_all_supported(void *arg)
   tt_str_op(msg, OP_EQ, "Sleen=0-4294967294");
   tor_free(msg);
 
-  /* If we get an unparseable list, we say "yes, that's supported." */
-#ifndef HAVE_RUST
-  // XXXX let's make this section unconditional: rust should behave the
-  // XXXX same as C here!
+  /* If we get a (barely) valid (but unsupported list, we say "yes, that's
+   * supported." */
+  tt_assert(protover_all_supported("Fribble=", &msg));
+  tt_ptr_op(msg, OP_EQ, NULL);
+
+  /* If we get a completely unparseable list, protover_all_supported should
+   * hit a fatal assertion for BUG(entries == NULL). */
   tor_capture_bugs_(1);
   tt_assert(protover_all_supported("Fribble", &msg));
-  tt_ptr_op(msg, OP_EQ, NULL);
   tor_end_capture_bugs_();
 
-  /* This case is forbidden. Since it came from a protover_all_supported,
-   * it can trigger a bug message.  */
+  /* If we get a completely unparseable list, protover_all_supported should
+   * hit a fatal assertion for BUG(entries == NULL). */
   tor_capture_bugs_(1);
   tt_assert(protover_all_supported("Sleen=0-4294967295", &msg));
-  tt_ptr_op(msg, OP_EQ, NULL);
-  tor_free(msg);
   tor_end_capture_bugs_();
-#endif
 
  done:
   tor_end_capture_bugs_();