diff --git a/config/webpack/configuration.js b/config/webpack/configuration.js
index cf8c0c7..4d325a8 100644
--- a/config/webpack/configuration.js
+++ b/config/webpack/configuration.js
@@ -7,7 +7,7 @@ const { readFileSync } = require('fs');
 
 const configPath = resolve('config', 'webpacker.yml');
 const loadersDir = join(__dirname, 'loaders');
-const settings = safeLoad(readFileSync(configPath), 'utf8')[env.NODE_ENV];
+const settings = safeLoad(readFileSync(configPath), 'utf8')[env.RAILS_ENV || env.NODE_ENV];
 
 const themePath = resolve('config', 'themes.yml');
 const themes = safeLoad(readFileSync(themePath), 'utf8');
diff --git a/config/webpacker.yml b/config/webpacker.yml
index 8d84706..ea814a0 100644
--- a/config/webpacker.yml
+++ b/config/webpacker.yml
@@ -40,6 +40,10 @@ test:
   # Compile test packs to a separate directory
   public_output_path: packs-test
 
+  # CircleCI precompiles packs prior to running the tests.
+  # Also avoids race conditions in parallel_tests.
+  compile: false
+
 production:
   <<: *default