diff --git a/jest.config.js b/jest.config.js
index b228ff773..638efec88 100644
--- a/jest.config.js
+++ b/jest.config.js
@@ -9,7 +9,7 @@ if (process.env.NODE_ENV === "production" || process.env.INSTALL_PACKAGE) {
 const { TEST_STANDALONE } = process.env;
 
 module.exports = {
-  setupFiles: ["<rootDir>/tests_config/run_spec.js"],
+  setupFiles: ["<rootDir>/tests_config/setup.js"],
   snapshotSerializers: [
     "jest-snapshot-serializer-raw",
     "jest-snapshot-serializer-ansi",
diff --git a/tests_config/run_spec.js b/tests_config/run_spec.js
index 795b2d091..cca8cdaca 100644
--- a/tests_config/run_spec.js
+++ b/tests_config/run_spec.js
@@ -82,7 +82,7 @@ const shouldThrowOnVerify = (filename, options) => {
 const isTestDirectory = (dirname, name) =>
   dirname.startsWith(path.join(__dirname, "../tests", name));
 
-global.run_spec = (fixtures, parsers, options) => {
+function runSpec(fixtures, parsers, options) {
   fixtures = typeof fixtures === "string" ? { dirname: fixtures } : fixtures;
   const { dirname } = fixtures;
 
@@ -307,7 +307,7 @@ global.run_spec = (fixtures, parsers, options) => {
       }
     });
   }
-};
+}
 
 function parse(source, options) {
   return prettier.__debug.parse(source, options, /* massage */ true).ast;
@@ -356,3 +356,5 @@ function format(text, options) {
     eolVisualizedOutput,
   };
 }
+
+module.exports = runSpec;
diff --git a/tests_config/setup.js b/tests_config/setup.js
new file mode 100644
index 000000000..5b979189c
--- /dev/null
+++ b/tests_config/setup.js
@@ -0,0 +1,7 @@
+"use strict";
+
+Object.defineProperty(global, "run_spec", {
+  get() {
+    return require("./run_spec.js");
+  },
+});