diff --git a/examples/src/main/kotlin/scientifik/kmath/bignum/BigIntegerBenchmark.kt b/examples/src/main/kotlin/scientifik/kmath/bignum/BigIntegerBenchmark.kt
index 069fb628e..d7c97a96b 100644
--- a/examples/src/main/kotlin/scientifik/kmath/bignum/BigIntegerBenchmark.kt
+++ b/examples/src/main/kotlin/scientifik/kmath/bignum/BigIntegerBenchmark.kt
@@ -1,7 +1,7 @@
 package scientifik.kmath.bignum
 
-import com.ionspin.kotlin.bignum.integer.BigInteger
 import scientifik.kmath.operations.BigIntField
+import scientifik.kmath.operations.JBigIntegerField
 import scientifik.kmath.operations.invoke
 import kotlin.concurrent.thread
 import kotlin.random.Random
@@ -9,30 +9,26 @@ import kotlin.system.measureTimeMillis
 
 private class BigIntegerBenchmark {
     fun java() {
-        invokeAndSum { l, l2 -> (l.toBigInteger() * l2.toBigInteger()).toLong() }
+        val random = Random(0)
+        var sum = JBigIntegerField.zero
+        repeat(1000000) {
+            sum += JBigIntegerField { number(random.nextInt()) * random.nextInt() }
+        }
+        println("java:$sum")
     }
 
     fun bignum() {
-        invokeAndSum { l, l2 -> (BigInteger.fromLong(l) * BigInteger.fromLong(l2)).longValue() }
+        val random = Random(0)
+        var sum = BigIntegerRing.zero
+        repeat(1000000) { sum += BigIntegerRing { number(random.nextInt()) * random.nextInt() } }
+        println("bignum:$sum")
     }
 
     fun bigint() {
-        invokeAndSum { l, l2 -> BigIntField { number(l) * number(l2) }.toString().toLong() }
-    }
-
-    fun long() {
-        invokeAndSum { l, l2 -> l * l2 }
-    }
-
-    private fun invokeAndSum(op: (Long, Long) -> Long) {
         val random = Random(0)
-        var sum = 0.0
-
-        repeat(1000000) {
-            sum += op(random.nextInt().toLong(), random.nextInt().toLong())
-        }
-
-        println(sum)
+        var sum = BigIntField.zero
+        repeat(1000000) { sum += BigIntField { number(random.nextInt()) * random.nextInt() } }
+        println("bigint:$sum")
     }
 }
 
@@ -53,9 +49,4 @@ fun main() {
         val bigint = measureTimeMillis(benchmark::bigint)
         println("bigint=$bigint")
     }
-
-    thread {
-        val long = measureTimeMillis(benchmark::long)
-        println("long=$long")
-    }
 }
diff --git a/kmath-bignum/src/commonMain/kotlin/scientifik/kmath/bignum/BigIntegerRing.kt b/kmath-bignum/src/commonMain/kotlin/scientifik/kmath/bignum/BigIntegerRing.kt
index f32ed61eb..d99d4934b 100644
--- a/kmath-bignum/src/commonMain/kotlin/scientifik/kmath/bignum/BigIntegerRing.kt
+++ b/kmath-bignum/src/commonMain/kotlin/scientifik/kmath/bignum/BigIntegerRing.kt
@@ -3,7 +3,7 @@ package scientifik.kmath.bignum
 import com.ionspin.kotlin.bignum.integer.BigInteger
 import scientifik.kmath.operations.Ring
 
-class BigIntegerRing : Ring<BigInteger> {
+object BigIntegerRing : Ring<BigInteger> {
     override val zero: BigInteger
         get() = BigInteger.ZERO