diff --git a/ops/machines/build01/default.nix b/ops/machines/build01/default.nix
index 393b32403..4dd8ffb60 100644
--- a/ops/machines/build01/default.nix
+++ b/ops/machines/build01/default.nix
@@ -27,6 +27,12 @@ in
     };
   };
 
+  # Put builds in /var/tmp as it can be quite big and would cause spurious
+  # failures from time to time: https://git.snix.dev/snix/snix/issues/82
+  systemd.services.nix-daemon.serviceConfig.Environment = [
+    "TMPDIR=/var/tmp"
+  ];
+
   services.depot.buildkite = {
     enable = true;
     agentCount = 32;