diff --git a/tests/setupTests.ts b/tests/setupTests.ts
index e1c96e0..6af41ab 100644
--- a/tests/setupTests.ts
+++ b/tests/setupTests.ts
@@ -6,7 +6,7 @@ const OLD_ENV = process.env;
 // in case the local machine already set these values.
 const processEnv = Object.fromEntries(
   Object.entries(process.env).filter(
-    ([key]) => key !== `FORCE_COLOR` && !key.startsWith(`COREPACK_`),
+    ([key]) => key !== `FORCE_COLOR` && key !== `DEBUG` && !key.startsWith(`COREPACK_`),
   ),
 );