diff --git a/build-constraints.yaml b/build-constraints.yaml
index b42212f2..0c71737c 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -931,6 +931,9 @@ expected-test-failures:
     # https://github.com/jswebtools/language-ecmascript/issues/60
     - language-ecmascript
 
+    # https://github.com/kazu-yamamoto/unix-time/issues/29
+    - unix-time
+
 # Haddocks which are expected to fail. Same concept as expected test failures.
 expected-haddock-failures:
     # https://github.com/acw/bytestring-progress/issues/4