diff --git a/src/test/kotlin/ru/dbotthepony/kommons/test/ComparatorTests.kt b/src/test/kotlin/ru/dbotthepony/kommons/test/ComparatorTests.kt
new file mode 100644
index 0000000..5910848
--- /dev/null
+++ b/src/test/kotlin/ru/dbotthepony/kommons/test/ComparatorTests.kt
@@ -0,0 +1,35 @@
+package ru.dbotthepony.kommons.test
+
+import it.unimi.dsi.fastutil.ints.IntComparators
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.DisplayName
+import org.junit.jupiter.api.Test
+import ru.dbotthepony.kommons.collect.addSorted
+import java.util.*
+import kotlin.collections.ArrayList
+
+object ComparatorTests {
+	@Test
+	@DisplayName("Comparator tests")
+	fun test() {
+		val sortedList = mutableListOf(1, 4, 6)
+		sortedList.addSorted(2, IntComparators.NATURAL_COMPARATOR)
+		sortedList.addSorted(3, IntComparators.NATURAL_COMPARATOR)
+		sortedList.addSorted(7, IntComparators.NATURAL_COMPARATOR)
+		sortedList.addSorted(-1, IntComparators.NATURAL_COMPARATOR)
+
+		assertEquals(mutableListOf(-1, 1, 2, 3, 4, 6, 7), sortedList)
+
+		val rand = Random()
+		val sorted2 = ArrayList<Int>()
+
+		for (i in 0 .. 100) {
+			sorted2.addSorted(rand.nextInt(-100, 100), IntComparators.NATURAL_COMPARATOR)
+		}
+
+		val sorted22 = ArrayList(sorted2)
+		sorted22.sort()
+
+		assertEquals(sorted22, sorted2)
+	}
+}