diff --git a/packages/surveys/src/components/buttons/back-button.tsx b/packages/surveys/src/components/buttons/back-button.tsx
index b3917ad124..af0f74d863 100644
--- a/packages/surveys/src/components/buttons/back-button.tsx
+++ b/packages/surveys/src/components/buttons/back-button.tsx
@@ -16,7 +16,7 @@ export function BackButton({ onClick, backButtonLabel, tabIndex = 2 }: BackButto
         "fb-border-back-button-border fb-text-heading focus:fb-ring-focus fb-rounded-custom fb-flex fb-items-center fb-border fb-px-3 fb-py-3 fb-text-base fb-font-medium fb-leading-4 fb-shadow-sm hover:fb-opacity-90 focus:fb-outline-none focus:fb-ring-2 focus:fb-ring-offset-2"
       )}
       onClick={onClick}>
-      {backButtonLabel ?? "Back"}
+      {backButtonLabel || "Back"}
     </button>
   );
 }
diff --git a/packages/surveys/src/components/buttons/submit-button.tsx b/packages/surveys/src/components/buttons/submit-button.tsx
index 33905cac85..bf8b522670 100644
--- a/packages/surveys/src/components/buttons/submit-button.tsx
+++ b/packages/surveys/src/components/buttons/submit-button.tsx
@@ -2,7 +2,7 @@ import { ButtonHTMLAttributes, useRef } from "preact/compat";
 import { useCallback, useEffect } from "preact/hooks";
 
 interface SubmitButtonProps extends ButtonHTMLAttributes<HTMLButtonElement> {
-  buttonLabel: string | undefined;
+  buttonLabel?: string;
   isLastQuestion: boolean;
   focus?: boolean;
 }
@@ -56,7 +56,7 @@ export function SubmitButton({
       className="fb-bg-brand fb-border-submit-button-border fb-text-on-brand focus:fb-ring-focus fb-rounded-custom fb-flex fb-items-center fb-border fb-px-3 fb-py-3 fb-text-base fb-font-medium fb-leading-4 fb-shadow-sm hover:fb-opacity-90 focus:fb-outline-none focus:fb-ring-2 focus:fb-ring-offset-2"
       onClick={onClick}
       disabled={disabled}>
-      {buttonLabel ?? (isLastQuestion ? "Finish" : "Next")}
+      {buttonLabel || (isLastQuestion ? "Finish" : "Next")}
     </button>
   );
 }