diff --git a/test/blackbox-tests/test-cases/vendor/run.t b/test/blackbox-tests/test-cases/vendor/run.t
index 00aa0537cfc6..531223c4f8fa 100644
--- a/test/blackbox-tests/test-cases/vendor/run.t
+++ b/test/blackbox-tests/test-cases/vendor/run.t
@@ -26,7 +26,7 @@ The vendored_dirs stanza is available from version 1.11 of the dune language
   Error: 'vendored_dirs' is only available since version 1.11 of the dune language
   [1]
 
-The same directory can be marked as both vendored and data-only
+The same directory cannot be marked as both vendored and data-only
 
   $ dune build --root conflicts-with-data-only
   Entering directory 'conflicts-with-data-only'