diff --git a/build-constraints.yaml b/build-constraints.yaml
index 0e8c508d..a21da924 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -5412,6 +5412,7 @@ expected-benchmark-failures:
     - raaz # https://github.com/commercialhaskell/stackage/issues/4766
     - thyme
     - xmlgen # https://github.com/skogsbaer/xmlgen/issues/6
+    - base64 # https://github.com/emilypi/base64/issues/5
 
 # end of expected-benchmark-failures