diff --git a/kotlin/src/main/java/com/baeldung/java/StringUtils.java b/kotlin/src/main/java/com/baeldung/java/StringUtils.java
new file mode 100644
index 0000000000..f405924cdf
--- /dev/null
+++ b/kotlin/src/main/java/com/baeldung/java/StringUtils.java
@@ -0,0 +1,7 @@
+package com.baeldung.java;
+
+public class StringUtils {
+    public static String toUpperCase(String name) {
+        return name.toUpperCase();
+    }
+}
diff --git a/kotlin/src/test/kotlin/com/baeldung/kotlin/KotlinScalaInteroperabilityTest.kt b/kotlin/src/test/kotlin/com/baeldung/kotlin/KotlinScalaInteroperabilityTest.kt
new file mode 100644
index 0000000000..f671c3af8b
--- /dev/null
+++ b/kotlin/src/test/kotlin/com/baeldung/kotlin/KotlinScalaInteroperabilityTest.kt
@@ -0,0 +1,20 @@
+package com.baeldung.kotlin
+
+import com.baeldung.java.StringUtils
+import org.junit.Test
+import kotlin.test.assertEquals
+
+
+class KotlinScalaInteroperabilityTest {
+    @Test
+    fun givenLowercaseString_whenExecuteMethodFromJavaStringUtils_shouldReturnStringUppercase() {
+        //given
+        val name = "tom"
+
+        //when
+        val res = StringUtils.toUpperCase(name)
+
+        //then
+        assertEquals(res, "TOM")
+    }
+}