diff --git a/build-constraints.yaml b/build-constraints.yaml
index d0f37cf4..f31ea923 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -217,6 +217,7 @@ packages:
     "Richard Cook <rcook@rcook.org> @rcook":
         - hidden-char
         - req-url-extra
+        - sexpr-parser
 
     "Vanessa McHale <tmchale@wisc.edu> @vmchale":
         - tibetan-utils < 0