diff --git a/.circleci/config.yml b/.circleci/config.yml
index 0a4eef767..cf41454de 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -193,7 +193,7 @@ commands:
     parameters:
       max-workers:
         type: integer
-        default: 3
+        default: 1
     steps:
       - run: yarn pretest
       - run:
@@ -276,7 +276,7 @@ jobs:
             - test-harness:
                 os: linux
                 node-version: << parameters.node-version >>
-                max-workers: 3
+                max-workers: 1
 
   test-browser:
     docker: