diff --git a/build-constraints.yaml b/build-constraints.yaml
index c03e8f78..70ff82c5 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -3880,6 +3880,9 @@ expected-haddock-failures:
 
     # https://github.com/fpco/stackage/pull/2652
     - haskell-lsp
+
+    # https://github.com/goldfirere/singletons/issues/242
+    - singletons
 # end of expected-haddock-failures
 
 # Benchmarks which should not be built. Note that Stackage builds benchmarks but does not run them.