diff --git a/core/src/main/kotlin/org/evomaster/core/search/gene/collection/ArrayGene.kt b/core/src/main/kotlin/org/evomaster/core/search/gene/collection/ArrayGene.kt
index ccb72649d6..75928d81d7 100644
--- a/core/src/main/kotlin/org/evomaster/core/search/gene/collection/ArrayGene.kt
+++ b/core/src/main/kotlin/org/evomaster/core/search/gene/collection/ArrayGene.kt
@@ -376,7 +376,10 @@ class ArrayGene<T>(
      */
     fun doesExist(gene: T): Boolean{
         if (!isElementApplicableToUniqueCheck(ParamUtil.getValueGene(gene))) return false
-        return elements.any { ParamUtil.getValueGene(it).containsSameValueAs(ParamUtil.getValueGene(gene)) }
+        return elements.any {
+            it.getLeafGene().javaClass == gene.getLeafGene().javaClass &&
+            it.getLeafGene().containsSameValueAs(gene.getLeafGene())
+        }
     }
 
     /**
diff --git a/core/src/test/kotlin/org/evomaster/core/search/gene/ArrayGeneTest.kt b/core/src/test/kotlin/org/evomaster/core/search/gene/ArrayGeneTest.kt
index 68bc3b7636..20f1586fff 100644
--- a/core/src/test/kotlin/org/evomaster/core/search/gene/ArrayGeneTest.kt
+++ b/core/src/test/kotlin/org/evomaster/core/search/gene/ArrayGeneTest.kt
@@ -2,12 +2,15 @@ package org.evomaster.core.search.gene
 
 import org.evomaster.core.search.gene.collection.ArrayGene
 import org.evomaster.core.search.gene.collection.EnumGene
+import org.evomaster.core.search.gene.numeric.BigIntegerGene
 import org.evomaster.core.search.gene.numeric.IntegerGene
 import org.evomaster.core.search.gene.numeric.LongGene
 import org.evomaster.core.search.gene.string.StringGene
 import org.evomaster.core.search.gene.utils.GeneUtils
+import org.evomaster.core.search.gene.wrapper.ChoiceGene
 import org.evomaster.core.search.service.Randomness
 import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertFalse
 import org.junit.jupiter.api.Assertions.assertTrue
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.assertThrows
@@ -207,4 +210,31 @@ class ArrayGeneTest {
         assertTrue(!xmlOutput.contains("]"), "XML should not contain square brackets")
         assertTrue(!xmlOutput.contains(", "), "XML must not contain commas with spaces")
     }
+
+    @Test
+    fun testDoesExistWithDifferentNumericGeneTypes() {
+        val bigIntegerGeneValue = java.math.BigInteger.valueOf(42L)
+        val bigIntegerGene = BigIntegerGene("bigInt", bigIntegerGeneValue)
+
+        val integerGeneValue = 42
+        val integerGene = IntegerGene("int", integerGeneValue)
+
+        val choiceGene = ChoiceGene("choice", listOf(bigIntegerGene, integerGene))
+
+        val arrayWithChoiceGenes = ArrayGene(
+            "arrayOfChoiceGenes",
+            template = ChoiceGene("template", listOf(bigIntegerGene, integerGene)),
+            elements = mutableListOf(choiceGene)
+        )
+
+        val anotherChoiceGene = ChoiceGene("choice", listOf(bigIntegerGene, integerGene))
+
+        choiceGene.selectActiveGene(0)
+        anotherChoiceGene.selectActiveGene(1)
+
+        assertFalse(arrayWithChoiceGenes.doesExist(anotherChoiceGene))
+
+    }
+
+
 }