diff --git a/dapp/src/router/index.tsx b/dapp/src/router/index.tsx
index 1a5b3ced0..351a8504e 100644
--- a/dapp/src/router/index.tsx
+++ b/dapp/src/router/index.tsx
@@ -38,9 +38,7 @@ export const router = createBrowserRouter([
       // TODO: display the error page/modal when the referral is invalid.
       const referralCodeFromUrl = referralProgram.getReferralFromURL()
 
-      const referralCode = referralProgram.isValidReferral(
-        Number(referralCodeFromUrl),
-      )
+      const referralCode = referralProgram.isValidReferral(referralCodeFromUrl)
         ? referralCodeFromUrl!
         : env.REFERRAL
 
diff --git a/dapp/src/utils/referralProgram.ts b/dapp/src/utils/referralProgram.ts
index 36f48b9a3..82a3bfbc5 100644
--- a/dapp/src/utils/referralProgram.ts
+++ b/dapp/src/utils/referralProgram.ts
@@ -9,9 +9,23 @@ const EMBEDDED_APP_TO_REFERRAL: Record<EmbedApp, number> = {
   "ledger-live": 2083,
 }
 
-const isValidReferral = (value: number) => {
-  const isInteger = Number.isInteger(value)
-  return isInteger && value >= 0 && value <= MAX_UINT16
+const isValidReferral = (value: unknown) => {
+  let valueAsNumber: number | undefined
+
+  if (typeof value === "string") {
+    // Only digits w/o leading zeros.
+    const isNumber = /^(?:[1-9][0-9]*|0)$/.test(value)
+    valueAsNumber = isNumber ? Number(value) : undefined
+  } else if (typeof value === "number") {
+    valueAsNumber = value
+  }
+
+  return (
+    !!valueAsNumber &&
+    Number.isInteger(valueAsNumber) &&
+    valueAsNumber >= 0 &&
+    valueAsNumber <= MAX_UINT16
+  )
 }
 
 const getReferralFromURL = () =>