diff --git a/src/env.d.ts b/src/env.d.ts
new file mode 100644
index 0000000..ae7e762
--- /dev/null
+++ b/src/env.d.ts
@@ -0,0 +1,7 @@
+export declare global {
+    namespace NodeJS {
+        interface ProcessEnv {
+            readonly NODE_ENV: 'development' | 'production' | 'test';
+        }
+    }
+}
\ No newline at end of file