diff --git a/frontend/interfaces/underscore.js b/frontend/interfaces/underscore.js
index 27e7fe0ed5df1da01a611920cbdf57ea1056c458..c0fd622b27ac9167a377d199446f8ec41ed810ff 100755
--- a/frontend/interfaces/underscore.js
+++ b/frontend/interfaces/underscore.js
@@ -71,7 +71,6 @@ declare module "underscore" {
   declare function isEmpty(o: any): boolean;
   declare function isString(o: any): boolean;
   declare function isObject(o: any): boolean;
-  declare function isArray(o: any): boolean;
 
   declare function groupBy<T>(
     a: Array<T>,
diff --git a/frontend/src/metabase/lib/request.js b/frontend/src/metabase/lib/request.js
index b910747b58bb84dfe7f51096208756b8b4a96cd4..1c46dc4053f6e8dc8ac40deb9fe72537d302a6ed 100644
--- a/frontend/src/metabase/lib/request.js
+++ b/frontend/src/metabase/lib/request.js
@@ -52,7 +52,7 @@ export class RestfulRequest {
 
   mergeToDictionary = (dict, result) => {
     dict = dict || {};
-    result = _.isArray(result)
+    result = Array.isArray(result)
       ? _.indexBy(result, "id")
       : { [result.id]: result };
 
diff --git a/frontend/test/metabase/scenarios/onboarding/auth/signin.cy.spec.js b/frontend/test/metabase/scenarios/onboarding/auth/signin.cy.spec.js
index 07d61b097cd2dd3094e85c51e18476ec8439c6a9..0facea506a95d974a17e00887802f6f40526ff1c 100644
--- a/frontend/test/metabase/scenarios/onboarding/auth/signin.cy.spec.js
+++ b/frontend/test/metabase/scenarios/onboarding/auth/signin.cy.spec.js
@@ -89,7 +89,7 @@ describe("scenarios > auth > signin", () => {
 
   sizes.forEach(size => {
     it(`should redirect from /auth/forgot_password back to /auth/login (viewport: ${size}) (metabase#12658)`, () => {
-      if (Cypress._.isArray(size)) {
+      if (Array.isArray(size)) {
         cy.viewport(size[0], size[1]);
       } else {
         cy.viewport(size);