diff --git a/bob/devtools/data/conda_build_config.yaml b/bob/devtools/data/conda_build_config.yaml
index b30febabef2f5e8c9a0616d8f72fbe78ecca34cf..03e19271c7a42de2a7a4d244f017461090e7c2bc 100644
--- a/bob/devtools/data/conda_build_config.yaml
+++ b/bob/devtools/data/conda_build_config.yaml
@@ -397,7 +397,7 @@ make:
   - 4.3
 matplotlib:
   - 3.4.3
-mkl:
+mkl:  # [x86 or x86_64]
   - 2020.4  # [x86 or x86_64]
 ncurses:
   - 6.2