diff --git a/core-java/src/main/java/com/baeldung/string/RemoveLastChar.java b/core-java/src/main/java/com/baeldung/string/RemoveLastChar.java
index 3816a61f45..faf30f7b25 100644
--- a/core-java/src/main/java/com/baeldung/string/RemoveLastChar.java
+++ b/core-java/src/main/java/com/baeldung/string/RemoveLastChar.java
@@ -10,7 +10,7 @@ package com.baeldung.string;
 public class RemoveLastChar {
 	public static String substring (String s) {
 		if (s == null || s.length() == 0) {
-			return null;
+			return s;
 		} else {
 			return (s.substring(0, s.length() - 1));
 		}
diff --git a/core-java/src/test/java/com/baeldung/string/RemoveLastCharTest.java b/core-java/src/test/java/com/baeldung/string/RemoveLastCharTest.java
index 80d76e96ac..a39212ced4 100644
--- a/core-java/src/test/java/com/baeldung/string/RemoveLastCharTest.java
+++ b/core-java/src/test/java/com/baeldung/string/RemoveLastCharTest.java
@@ -26,6 +26,7 @@ public class RemoveLastCharTest {
 	public void givenTestString_substring_getStingWithoutLastChar() {
 		Assert.assertEquals("abcde", RemoveLastChar.substring(TEST_STRING));
 		Assert.assertEquals("abcde", StringUtils.chop(TEST_STRING));
+		Assert.assertEquals("abcde", StringUtils.substring(TEST_STRING, 0, TEST_STRING.length() - 1));
 	}
 	
 	@Test
@@ -37,20 +38,25 @@ public class RemoveLastCharTest {
 
 	@Test
 	public void givenEmptyString_substring_getEmptyString() {
-		Assert.assertEquals(NULL_STRING, RemoveLastChar.substring(EMPTY_STRING));
-		Assert.assertEquals(NULL_STRING, StringUtils.chop(NULL_STRING));
+		Assert.assertEquals(EMPTY_STRING, RemoveLastChar.substring(EMPTY_STRING));
+		Assert.assertEquals(EMPTY_STRING, StringUtils.chop(EMPTY_STRING));
+		Assert.assertEquals(EMPTY_STRING, StringUtils.substring(EMPTY_STRING, 0, EMPTY_STRING.length() - 1));
+
 	}
 	
 	@Test
 	public void givenOneCharString_substring_getEmptyString() {
 		Assert.assertEquals(EMPTY_STRING, RemoveLastChar.substring(ONE_CHAR_STRING));
 		Assert.assertEquals(EMPTY_STRING, StringUtils.chop(ONE_CHAR_STRING));
+		Assert.assertEquals(EMPTY_STRING, StringUtils.substring(ONE_CHAR_STRING, 0, ONE_CHAR_STRING.length() - 1));
+
 	}
 	
 	@Test
 	public void givenStringWithWhiteSpaceAtTheEnd_substring_getStringWithoutWhiteSpaceAtTheEnd() {
 		Assert.assertEquals("abc", RemoveLastChar.substring(WHITE_SPACE_AT_THE_END_STRING));
 		Assert.assertEquals("abc", StringUtils.chop(WHITE_SPACE_AT_THE_END_STRING));
+		Assert.assertEquals("abc", StringUtils.substring(WHITE_SPACE_AT_THE_END_STRING, 0, WHITE_SPACE_AT_THE_END_STRING.length() - 1));
 	}
 	
 }