diff --git a/lib/util/exec/env.ts b/lib/util/exec/env.ts
index cf53afd966df60acb7ea99cbb979181d46903058..a83824a19bfbb51db86765f73eb3c99f8a766b47 100644
--- a/lib/util/exec/env.ts
+++ b/lib/util/exec/env.ts
@@ -29,6 +29,7 @@ const basicEnvVars = [
   'COREPACK_ENABLE_NETWORK',
   'COREPACK_ENABLE_STRICT',
   'COREPACK_ENABLE_PROJECT_SPEC',
+  'COREPACK_ENABLE_UNSAFE_CUSTOM_URLS',
   'COREPACK_HOME',
   'COREPACK_NPM_REGISTRY',
   'COREPACK_NPM_TOKEN',