diff --git a/.env b/.env
index 5b70f0c87..8120b4c41 100644
--- a/.env
+++ b/.env
@@ -10,8 +10,9 @@ RUST_LOG_FORMAT=full
 ASYNC_STD_THREAD_COUNT=1
 # Rayon is only used occasionally when generating a light client proof. Allow it to use 2 threads to
 # speed up proof generation, but still don't use every available core or else the demo is too
-# heavyweight.
-RAYON_NUM_THREADS=2
+# heavyweight. To avoid interfering with the use of rayon elsewhere we don't set RAYON_NUM_THREADS
+# var directly, but only when running the prover services in demos.
+PROVER_RAYON_NUM_THREADS=2
 
 # Internal port inside container
 ESPRESSO_CDN_SERVER_PORT=40000
diff --git a/docker-compose.yaml b/docker-compose.yaml
index 92f1ccac0..0ee69ffa1 100644
--- a/docker-compose.yaml
+++ b/docker-compose.yaml
@@ -142,6 +142,7 @@ services:
       - ESPRESSO_SEQUENCER_LIGHTCLIENT_ADDRESS
       - MNEMONIC=$ESPRESSO_SEQUENCER_ETH_MNEMONIC
       - ESPRESSO_SEQUENCER_STATE_PROVER_ACCOUNT_INDEX
+      - RAYON_NUM_THREADS=$PROVER_RAYON_NUM_THREADS
       - RUST_LOG
       - RUST_LOG_FORMAT
       - ASYNC_STD_THREAD_COUNT
diff --git a/flake.lock b/flake.lock
index c34c4ec02..832aab8c3 100644
--- a/flake.lock
+++ b/flake.lock
@@ -196,11 +196,11 @@
         "nixpkgs": "nixpkgs"
       },
       "locked": {
-        "lastModified": 1709457044,
-        "narHash": "sha256-1SktmSjTjC1rhJwQ+kvqUeExKogNzserFGuoGwOerHw=",
+        "lastModified": 1712135466,
+        "narHash": "sha256-+xFfYk17EI0zZTGmhh3MyeSpl7RVohoVp/4HaSvGj4I=",
         "owner": "shazow",
         "repo": "foundry.nix",
-        "rev": "592e8ca2e82a2c3a8d0d4dcc7f7c5b8c3842efcd",
+        "rev": "ece7c960a440c6725a7a5576d1f49a5fabde3747",
         "type": "github"
       },
       "original": {
diff --git a/process-compose.yaml b/process-compose.yaml
index 8b60c364d..451207f50 100644
--- a/process-compose.yaml
+++ b/process-compose.yaml
@@ -66,6 +66,7 @@ processes:
       - MNEMONIC=$ESPRESSO_SEQUENCER_ETH_MNEMONIC
       - ESPRESSO_SEQUENCER_STAKE_TABLE_CAPACITY=10
       - ESPRESSO_STATE_PROVER_UPDATE_INTERVAL=30s
+      - RAYON_NUM_THREADS=$PROVER_RAYON_NUM_THREADS
     depends_on:
       orchestrator:
         condition: process_healthy