diff --git a/src/test/java/com/thealgorithms/strings/UpperTest.java b/src/test/java/com/thealgorithms/strings/UpperTest.java
new file mode 100644
index 000000000..542b175c9
--- /dev/null
+++ b/src/test/java/com/thealgorithms/strings/UpperTest.java
@@ -0,0 +1,17 @@
+package com.thealgorithms.strings;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class UpperTest {
+    @Test
+    public void toUpperCase() {
+        String input1 = "hello world";
+        String input2 = "hElLo WoRlD";
+        String input3 = "HELLO WORLD";
+        assertEquals("HELLO WORLD", Upper.toUpperCase(input1));
+        assertEquals("HELLO WORLD", Upper.toUpperCase(input2));
+        assertEquals("HELLO WORLD", Upper.toUpperCase(input3));
+    }
+}