diff --git a/build-constraints.yaml b/build-constraints.yaml
index 66435994..9e6b9c97 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -4053,6 +4053,7 @@ expected-test-failures:
     - http-link-header # https://github.com/myfreeweb/http-link-header/issues/7
     - courier # https://github.com/hargettp/courier/issues/19
     - main-tester # https://github.com/fpco/stackage/pull/3528
+    - microformats2-parser # https://github.com/myfreeweb/microformats2-parser/issues/5
 
     # Compilation failures
     - yeshql # https://bitbucket.org/tdammers/yeshql/issues/1/stackage-nightly-test-failure