diff --git a/build-constraints.yaml b/build-constraints.yaml
index abf1e978..0207887e 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -1027,6 +1027,9 @@ expected-test-failures:
     # https://github.com/zmthy/http-media/issues/11
     - http-media
 
+    # https://github.com/ekmett/semigroupoids/issues/18
+    - semigroupoids
+
 # Haddocks which are expected to fail. Same concept as expected test failures.
 expected-haddock-failures:
     # https://github.com/acw/bytestring-progress/issues/4