diff --git a/lib/entry-points.js b/lib/entry-points.js
index 0cf4dc2bc..2fcf8c198 100644
--- a/lib/entry-points.js
+++ b/lib/entry-points.js
@@ -141488,6 +141488,10 @@ var ReadOnlyEnv = class {
     this.vars = vars;
   }
   vars;
+  /** Clones the object while detaching the underlying environment from the original. */
+  clone() {
+    return Object.create(this, { vars: { value: { ...this.vars } } });
+  }
   /** Tries to get the value for `name` and throws if there isn't one. */
   getRequired(name) {
     return getRequiredEnvVar(this.vars, name);
diff --git a/src/environment.ts b/src/environment.ts
index 9d52a903f..1b00ab7cf 100644
--- a/src/environment.ts
+++ b/src/environment.ts
@@ -265,6 +265,11 @@ export function getOptionalEnvVar(paramName: string): string | undefined {
 export class ReadOnlyEnv<T extends string | undefined = string | undefined> {
   constructor(protected readonly vars: Record<string, T>) {}
 
+  /** Clones the object while detaching the underlying environment from the original. */
+  public clone(): this {
+    return Object.create(this, { vars: { value: { ...this.vars } } }) as this;
+  }
+
   /** Tries to get the value for `name` and throws if there isn't one. */
   public getRequired(name: string): string {
     return getRequiredEnvVar(this.vars, name);
diff --git a/src/testing-utils.ts b/src/testing-utils.ts
index f630082be..92fad068e 100644
--- a/src/testing-utils.ts
+++ b/src/testing-utils.ts
@@ -240,7 +240,7 @@ abstract class BaseEnvBuilder<
       cloneFrom !== undefined
         ? ({
             ...cloneFrom.state,
-            env: Object.create(cloneFrom.state.env),
+            env: cloneFrom.state.env.clone(),
             actions: Object.create(cloneFrom.state.actions),
             logger: this.logger,
           } satisfies ActionState<AllState>)