diff --git a/infra/files/compose.yml b/infra/files/compose.yml
index 0a644028..046c72fc 100644
--- a/infra/files/compose.yml
+++ b/infra/files/compose.yml
@@ -104,6 +104,12 @@ services:
     # The image runs as 65532, so as with Jetstream there is no capability
     # for it to keep.
     cap_drop: [ALL]
+    # glibc keeps a heap per arena, up to eight arenas a core, and seldom
+    # hands back what they free. Both binaries build large /view bodies from
+    # many threads, so that is most of their resident memory; two arenas keep
+    # each at a plateau.
+    environment: &arenas
+      MALLOC_ARENA_MAX: "2"
     volumes:
       - /opt/vibescrobble/data:/data
     command:
@@ -172,6 +178,7 @@ services:
     <<: *service
     depends_on: [index]
     cap_drop: [ALL]
+    environment: *arenas
     command:
       - vibescrobble-query
       - --index