diff --git a/.circleci/config.yml b/.circleci/config.yml
index 61e8b2331beb272b356671aeee9e47cbdc8b941a..494208c068b8637d73c63a9cebfa138f5c0995b7 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -125,7 +125,7 @@ jobs:
             #
             # Also limit the number of concurrent jobs because of resource
             # constraints on CircleCI. :/
-            nix-build --max-jobs 1 --argstr hypothesisProfile ci --arg collectCoverage true --attr doc
+            nix-build --cores 1 --max-jobs 1 --argstr hypothesisProfile ci --arg collectCoverage true --attr doc
 
       - run:
           name: "Cache codecov"