diff --git a/Tests/AcknowExampleTests/AcknowListViewControllerTests.swift b/Tests/AcknowExampleTests/AcknowListViewControllerTests.swift
index 4e5cd93..a13a4bf 100644
--- a/Tests/AcknowExampleTests/AcknowListViewControllerTests.swift
+++ b/Tests/AcknowExampleTests/AcknowListViewControllerTests.swift
@@ -25,6 +25,21 @@ class AcknowListViewControllerTests: XCTestCase {
         XCTAssertEqual(cell.textLabel?.text, "AcknowList")
     }
     
+    func testLocalizedStringReturnsDefault() {
+        
+        class MockAcknowListViewController: AcknowListViewController {
+            
+            override class func preferredLanguageCode() -> String {
+                return "qq-QQ"
+            }
+        }
+        
+        XCTAssertEqual("Acknowledgements", MockAcknowListViewController.localizedString(forKey: "VTAckAcknowledgements", defaultString: ""))
+        
+        XCTAssertEqual("Generated by CocoaPods", MockAcknowListViewController.localizedString(forKey: "VTAckGeneratedByCocoaPods", defaultString: ""))
+    }
+
+    
     func testLocalizedStringReturnsEnglish() {
         
         class MockAcknowListViewController: AcknowListViewController {
@@ -39,6 +54,34 @@ class AcknowListViewControllerTests: XCTestCase {
         XCTAssertEqual("Generated by CocoaPods", MockAcknowListViewController.localizedString(forKey: "VTAckGeneratedByCocoaPods", defaultString: ""))
     }
     
+    func testLocalizedStringReturnsEnglishUS() {
+        
+        class MockAcknowListViewController: AcknowListViewController {
+            
+            override class func preferredLanguageCode() -> String {
+                return "en-US"
+            }
+        }
+        
+        XCTAssertEqual("Acknowledgements", MockAcknowListViewController.localizedString(forKey: "VTAckAcknowledgements", defaultString: ""))
+        
+        XCTAssertEqual("Generated by CocoaPods", MockAcknowListViewController.localizedString(forKey: "VTAckGeneratedByCocoaPods", defaultString: ""))
+    }
+    
+    func testLocalizedStringReturnsFrenchForShortLanguageCode() {
+        
+        class MockAcknowListViewController: AcknowListViewController {
+            
+            override class func preferredLanguageCode() -> String {
+                return "fr"
+            }
+        }
+        
+        XCTAssertEqual("Remerciements", MockAcknowListViewController.localizedString(forKey: "VTAckAcknowledgements", defaultString: ""))
+        
+        XCTAssertEqual("Généré par CocoaPods", MockAcknowListViewController.localizedString(forKey: "VTAckGeneratedByCocoaPods", defaultString: ""))
+    }
+    
     func testLocalizedStringReturnsFrench() {
         
         class MockAcknowListViewController: AcknowListViewController {