diff --git a/spack-environment/packages.yaml b/spack-environment/packages.yaml
index 6aa44f0d0356168107a6d3146e9c0dc5d2e24e68..61d51ec3b8229dc5f647dd448136d80976a0a33c 100644
--- a/spack-environment/packages.yaml
+++ b/spack-environment/packages.yaml
@@ -32,7 +32,7 @@ packages:
     - +root +zlib
   algorithms:
     require:
-    - '@main'
+    - '@main=master'
   cairo:
     require:
     - '@1.16.0'