diff --git a/core-java-modules/core-java-string-operations-3/src/main/java/com/baeldung/stringfilenamevalidaiton/StringFilenameValidationUtils.java b/core-java-modules/core-java-string-operations-3/src/main/java/com/baeldung/stringfilenamevalidaiton/StringFilenameValidationUtils.java
index 1a86edd45a..c1af75eca1 100644
--- a/core-java-modules/core-java-string-operations-3/src/main/java/com/baeldung/stringfilenamevalidaiton/StringFilenameValidationUtils.java
+++ b/core-java-modules/core-java-string-operations-3/src/main/java/com/baeldung/stringfilenamevalidaiton/StringFilenameValidationUtils.java
@@ -7,7 +7,7 @@ import java.util.Arrays;
 
 public class StringFilenameValidationUtils {
 
-    public static final Character[] INVALID_WINDOWS_SPECIFIC_CHARS = {'"', '*', ':', '<', '>', '?', '\\', '|', 0x7F};
+    public static final Character[] INVALID_WINDOWS_SPECIFIC_CHARS = {'"', '*', ':', '<', '>', '?', '\\', '|', '/'};
     public static final Character[] INVALID_UNIX_SPECIFIC_CHARS = {'\000'};
 
     public static final String REGEX_PATTERN = "^[A-za-z0-9.]{1,255}$";
diff --git a/core-java-modules/core-java-string-operations-3/src/test/java/com/baeldung/stringfilenamevalidaiton/StringFilenameValidationUnitTest.java b/core-java-modules/core-java-string-operations-3/src/test/java/com/baeldung/stringfilenamevalidaiton/StringFilenameValidationUnitTest.java
index 3e787f08be..04f6b83183 100644
--- a/core-java-modules/core-java-string-operations-3/src/test/java/com/baeldung/stringfilenamevalidaiton/StringFilenameValidationUnitTest.java
+++ b/core-java-modules/core-java-string-operations-3/src/test/java/com/baeldung/stringfilenamevalidaiton/StringFilenameValidationUnitTest.java
@@ -2,6 +2,7 @@ package com.baeldung.stringfilenamevalidaiton;
 
 import org.apache.commons.lang3.RandomStringUtils;
 import org.apache.commons.lang3.RandomUtils;
+import org.assertj.core.api.InstanceOfAssertFactories;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.condition.EnabledOnOs;
 import org.junit.jupiter.api.condition.OS;
@@ -79,17 +80,21 @@ public class StringFilenameValidationUnitTest {
     @ParameterizedTest
     @EnabledOnOs(OS.WINDOWS)
     @MethodSource("filenamesWithInvalidWindowsChars")
-    public void givenFilenameStringWithInvalidWindowsCharAndIsWindows_whenValidateUsingIO_thenRaiseException(String filename) {
-        assertThatThrownBy(() -> validateStringFilenameUsingIO(filename))
-            .isInstanceOf(IOException.class)
-            .hasMessageContaining("Invalid file path");
+	public void givenFilenameStringWithInvalidWindowsCharAndIsWindows_whenValidateUsingIO_thenRaiseException(
+			String filename) {
+		if (!filename.contains(":")) {
+			assertThatThrownBy(() -> validateStringFilenameUsingIO(filename)).isInstanceOf(IOException.class)
+					.extracting(Throwable::getMessage, InstanceOfAssertFactories.STRING)
+					.containsAnyOf("The system cannot find the path specifie",
+							"The filename, directory name, or volume label syntax is incorrect");
+			if (!filename.contains("/") && !filename.contains("\\")) {
+				assertThatThrownBy(() -> validateStringFilenameUsingNIO2(filename))
+						.isInstanceOf(InvalidPathException.class).hasMessageContaining("Illegal char");
+			}
+		}
 
-        assertThatThrownBy(() -> validateStringFilenameUsingNIO2(filename))
-            .isInstanceOf(InvalidPathException.class)
-            .hasMessage("character not allowed");
-
-        assertThat(validateStringFilenameUsingContains(filename)).isFalse();
-    }
+		assertThat(validateStringFilenameUsingContains(filename)).isFalse();
+	}
 
     @ParameterizedTest
     @EnabledOnOs({OS.LINUX, OS.MAC})