diff --git a/jest.config.js b/jest.config.js
index 31005a6586..4f33c3d8c0 100644
--- a/jest.config.js
+++ b/jest.config.js
@@ -12,4 +12,11 @@ module.exports = {
       statements: 38, // Increase this percentage as test coverage improves
     },
   },
+  globals: {
+    // Revert when memory leak in ts-jest is fixed.
+    // See https://github.com/kulshekhar/ts-jest/issues/1967.
+    'ts-jest': {
+      isolatedModules: true,
+    },
+  },
 }