diff --git a/build-constraints.yaml b/build-constraints.yaml
index cfada449..86d4a473 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -7530,6 +7530,7 @@ expected-benchmark-failures:
     - incremental-parser # 0.5.0.2
     - lz4 # https://github.com/fpco/stackage/issues/3510
     - raaz # https://github.com/commercialhaskell/stackage/issues/4766
+    - sexp-grammar # https://github.com/esmolanka/sexp-grammar/issues/21
     - thyme
     - universum
     - xmlgen # https://github.com/skogsbaer/xmlgen/issues/6