diff --git a/Userland/Libraries/LibJS/Runtime/BigInt.cpp b/Userland/Libraries/LibJS/Runtime/BigInt.cpp
index 8c0b8a443f..6cf4306c6c 100644
--- a/Userland/Libraries/LibJS/Runtime/BigInt.cpp
+++ b/Userland/Libraries/LibJS/Runtime/BigInt.cpp
@@ -22,6 +22,11 @@ BigInt::BigInt(Crypto::SignedBigInteger big_integer)
     VERIFY(!m_big_integer.is_invalid());
 }
 
+ErrorOr<String> BigInt::to_string() const
+{
+    return String::formatted("{}n", TRY(m_big_integer.to_base(10)));
+}
+
 // 21.2.1.1.1 NumberToBigInt ( number ), https://tc39.es/ecma262/#sec-numbertobigint
 ThrowCompletionOr<BigInt*> number_to_bigint(VM& vm, Value number)
 {
diff --git a/Userland/Libraries/LibJS/Runtime/BigInt.h b/Userland/Libraries/LibJS/Runtime/BigInt.h
index b5df053366..bb937a71e4 100644
--- a/Userland/Libraries/LibJS/Runtime/BigInt.h
+++ b/Userland/Libraries/LibJS/Runtime/BigInt.h
@@ -6,6 +6,8 @@
 
 #pragma once
 
+#include <AK/Error.h>
+#include <AK/String.h>
 #include <AK/StringView.h>
 #include <LibCrypto/BigInt/SignedBigInteger.h>
 #include <LibJS/Heap/Cell.h>
@@ -21,7 +23,9 @@ public:
     virtual ~BigInt() override = default;
 
     Crypto::SignedBigInteger const& big_integer() const { return m_big_integer; }
-    const DeprecatedString to_deprecated_string() const { return DeprecatedString::formatted("{}n", m_big_integer.to_base_deprecated(10)); }
+
+    ErrorOr<String> to_string() const;
+    DeprecatedString to_deprecated_string() const { return DeprecatedString::formatted("{}n", m_big_integer.to_base_deprecated(10)); }
 
 private:
     explicit BigInt(Crypto::SignedBigInteger);