diff --git a/build-constraints.yaml b/build-constraints.yaml
index 06df6e9e..b7013eb0 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -5985,6 +5985,7 @@ expected-test-failures:
     - async-timer # https://github.com/mtesseract/async-timer/issues/8
     - commutative # https://github.com/athanclark/commutative/issues/4
     - conduit-throttle # https://github.com/mtesseract/conduit-throttle/issues/12
+    - fitspec # https://github.com/commercialhaskell/stackage/issues/6026
     - haddock
     - haskell-tools-builtin-refactorings
     - hweblib # https://github.com/aycanirican/hweblib/issues/3