diff --git a/build-constraints.yaml b/build-constraints.yaml
index 2eee9225..7b280fee 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -3031,7 +3031,7 @@ packages:
 
     "Alexander Ignatyev <ignatyev.alexander@gmail.com> @alexander-ignatyev":
         - astro
-        - mltool
+        # - mltool # https://github.com/Alexander-Ignatyev/mltool/issues/2
         - hmatrix-morpheus
 
     "Edward Amsden <edwardamsden@gmail.com> @eamsden":