diff --git a/packages/hardhat-core/test/builtin-tasks/flatten.ts b/packages/hardhat-core/test/builtin-tasks/flatten.ts
index cc5c508816..6249b3cf1c 100644
--- a/packages/hardhat-core/test/builtin-tasks/flatten.ts
+++ b/packages/hardhat-core/test/builtin-tasks/flatten.ts
@@ -416,14 +416,17 @@ describe("Flatten task", () => {
 
     it("should write to an output file when the parameter output is specified", async function () {
       const outputFile = `${tmpdir()}/flatten.sol`;
-      await this.env.run(TASK_FLATTEN, {
-        files: ["contracts/A.sol", "contracts/D.sol"],
-        output: outputFile,
-      });
-      const expected = await getExpectedSol();
-      const actual = readFileSync(outputFile, "utf8");
-      assert.equal(actual, expected);
-      removeSync(outputFile);
+      try {
+        await this.env.run(TASK_FLATTEN, {
+          files: ["contracts/A.sol", "contracts/D.sol"],
+          output: outputFile,
+        });
+        const expected = await getExpectedSol();
+        const actual = readFileSync(outputFile, "utf8");
+        assert.equal(actual, expected);
+      } finally {
+        removeSync(outputFile);
+      }
     });
 
     describe("No contracts to flatten", () => {