diff --git a/spack-environment/packages.yaml b/spack-environment/packages.yaml
index 22fec35e3a21c8d77c873d3d2a051d527f5abe53..194517d69d266cd6527fd978170eb5c4dcde3a5a 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'