diff --git a/src/CheckSessionIFrame.ts b/src/CheckSessionIFrame.ts
index 4fdc1a4cc..5bef28c07 100644
--- a/src/CheckSessionIFrame.ts
+++ b/src/CheckSessionIFrame.ts
@@ -3,12 +3,10 @@
 
 import { Log } from "./utils";
 
-const DefaultInterval = 2000;
-
 export class CheckSessionIFrame {
     private _callback: () => Promise<void> | void;
     private _client_id: string;
-    private _interval: number;
+    private _intervalInSeconds: number;
     private _stopOnError: boolean;
     private _frame_origin: string;
     private _frame: HTMLIFrameElement;
@@ -16,11 +14,11 @@ export class CheckSessionIFrame {
     private _timer: number | null;
     private _session_state: string | null;
 
-    public constructor(callback: () => Promise<void> | void, client_id: string, url: string, interval?: number, stopOnError?: boolean) {
+    public constructor(callback: () => Promise<void> | void, client_id: string, url: string, intervalInSeconds: number, stopOnError: boolean) {
         this._callback = callback;
         this._client_id = client_id;
-        this._interval = interval || DefaultInterval;
-        this._stopOnError = stopOnError || true;
+        this._intervalInSeconds = intervalInSeconds;
+        this._stopOnError = stopOnError;
 
         const idx = url.indexOf("/", url.indexOf("//") + 2);
         this._frame_origin = url.substr(0, idx);
@@ -96,7 +94,7 @@ export class CheckSessionIFrame {
         send();
 
         // and setup timer
-        this._timer = window.setInterval(send, this._interval);
+        this._timer = window.setInterval(send, this._intervalInSeconds * 1000);
     }
 
     public stop() {
diff --git a/src/SessionMonitor.ts b/src/SessionMonitor.ts
index 43a3ff241..691b8c7a1 100644
--- a/src/SessionMonitor.ts
+++ b/src/SessionMonitor.ts
@@ -82,10 +82,10 @@ export class SessionMonitor {
                         Log.debug("SessionMonitor._start: Initializing check session iframe");
 
                         const client_id = this._userManager.settings.client_id;
-                        const interval = this._userManager.settings.checkSessionInterval;
+                        const intervalInSeconds = this._userManager.settings.checkSessionIntervalInSeconds;
                         const stopOnError = this._userManager.settings.stopCheckSessionOnError;
 
-                        this._checkSessionIFrame = new CheckSessionIFrame(this._callback.bind(this), client_id, url, interval, stopOnError);
+                        this._checkSessionIFrame = new CheckSessionIFrame(this._callback.bind(this), client_id, url, intervalInSeconds, stopOnError);
                         await this._checkSessionIFrame.load();
                         this._checkSessionIFrame &&
                         this._checkSessionIFrame.start(session_state);
diff --git a/src/UserManagerSettings.ts b/src/UserManagerSettings.ts
index c50fb7819..abbc5e416 100644
--- a/src/UserManagerSettings.ts
+++ b/src/UserManagerSettings.ts
@@ -6,7 +6,7 @@ import { WebStorageStateStore } from "./WebStorageStateStore";
 import { SigninRequest } from "./SigninRequest";
 
 const DefaultAccessTokenExpiringNotificationTimeInSeconds = 60;
-const DefaultCheckSessionInterval = 2000;
+const DefaultCheckSessionIntervalInSeconds = 2;
 
 export interface UserManagerSettings extends OidcClientSettings {
     /** The URL for the page containing the call to signinPopupCallback to handle the callback from the OIDC/OAuth2 */
@@ -32,8 +32,8 @@ export interface UserManagerSettings extends OidcClientSettings {
     /** Will raise events for when user has performed a signout at the OP (default: true) */
     monitorSession?: boolean;
     monitorAnonymousSession?: boolean;
-    /** Interval, in ms, to check the user's session (default: 2000) */
-    checkSessionInterval?: number;
+    /** Interval in seconds to check the user's session (default: 2) */
+    checkSessionIntervalInSeconds?: number;
     query_status_response_type?: string;
     stopCheckSessionOnError?: boolean;
 
@@ -60,9 +60,9 @@ export class UserManagerSettingsStore extends OidcClientSettingsStore {
 
     public readonly monitorSession: boolean;
     public readonly monitorAnonymousSession: boolean;
-    public readonly checkSessionInterval: number;
+    public readonly checkSessionIntervalInSeconds: number;
     public readonly query_status_response_type: string | undefined;
-    public readonly stopCheckSessionOnError: boolean | undefined;
+    public readonly stopCheckSessionOnError: boolean;
 
     public readonly revokeAccessTokenOnSignout: boolean;
     public readonly accessTokenExpiringNotificationTimeInSeconds: number;
@@ -82,7 +82,7 @@ export class UserManagerSettingsStore extends OidcClientSettingsStore {
             includeIdTokenInSilentRenew = true,
             monitorSession = true,
             monitorAnonymousSession = false,
-            checkSessionInterval = DefaultCheckSessionInterval,
+            checkSessionIntervalInSeconds = DefaultCheckSessionIntervalInSeconds,
             stopCheckSessionOnError = true,
             query_status_response_type,
             revokeAccessTokenOnSignout = false,
@@ -105,7 +105,7 @@ export class UserManagerSettingsStore extends OidcClientSettingsStore {
 
         this.monitorSession = monitorSession;
         this.monitorAnonymousSession = monitorAnonymousSession;
-        this.checkSessionInterval = checkSessionInterval;
+        this.checkSessionIntervalInSeconds = checkSessionIntervalInSeconds;
         this.stopCheckSessionOnError = stopCheckSessionOnError;
         if (query_status_response_type) {
             this.query_status_response_type = query_status_response_type;
diff --git a/test/unit/UserManagerSettings.test.ts b/test/unit/UserManagerSettings.test.ts
index bb64768cf..8477d4447 100644
--- a/test/unit/UserManagerSettings.test.ts
+++ b/test/unit/UserManagerSettings.test.ts
@@ -279,11 +279,11 @@ describe("UserManagerSettings", () => {
                 authority: "authority",
                 client_id: "client",
                 redirect_uri: "redirect",
-                checkSessionInterval : 6000
+                checkSessionIntervalInSeconds: 6
             });
 
             // assert
-            expect(subject.checkSessionInterval).toEqual(6000);
+            expect(subject.checkSessionIntervalInSeconds).toEqual(6);
         });
         it("should use default value", () => {
             // act
@@ -294,7 +294,7 @@ describe("UserManagerSettings", () => {
             });
 
             // assert
-            expect(subject.checkSessionInterval).toEqual(2000);
+            expect(subject.checkSessionIntervalInSeconds).toEqual(2);
         });
     });