diff --git a/src/etapi/etapi_utils.test.ts b/src/etapi/etapi_utils.test.ts
new file mode 100644
index 000000000..4c9d9823f
--- /dev/null
+++ b/src/etapi/etapi_utils.test.ts
@@ -0,0 +1,12 @@
+import etapiUtils = require("./etapi_utils");
+const EtapiError = etapiUtils.EtapiError;
+
+describe("EtapiError", () => {
+    it("should support instanceof", () => {
+        const anError = new etapiUtils.EtapiError(404, "123", "test");
+        expect(anError instanceof EtapiError).toBeTruthy();
+        expect(anError instanceof Error).toBeTruthy();
+        expect(new Error("Test") instanceof EtapiError).toBeFalsy();
+        anError.foo();
+    });
+});
\ No newline at end of file
diff --git a/src/etapi/etapi_utils.ts b/src/etapi/etapi_utils.ts
index bcb589325..1bd75b4ca 100644
--- a/src/etapi/etapi_utils.ts
+++ b/src/etapi/etapi_utils.ts
@@ -23,6 +23,10 @@ class EtapiError extends Error {
         this.code = code;
         this.message = message;
     }
+
+    foo() {
+        console.log("bar");
+    }
 }
 
 function sendError(res: Response, statusCode: number, code: string, message: string) {