diff --git a/sample/src/main/java/com/rubengees/introductionsample/MainActivity.java b/sample/src/main/java/com/rubengees/introductionsample/MainActivity.java
index 06444a9..bb8f63a 100644
--- a/sample/src/main/java/com/rubengees/introductionsample/MainActivity.java
+++ b/sample/src/main/java/com/rubengees/introductionsample/MainActivity.java
@@ -47,7 +47,8 @@
 
 public class MainActivity extends AppCompatActivity {
 
-    public static final String ERROR_API_LEVEL = "You need at least API 11 for this feature";
+    private static final String ERROR_API_LEVEL = "You need at least API 11 for this feature";
+
     private IntroductionConfiguration.OnSlideListener defaultOnSlideListener =
             new IntroductionConfiguration.OnSlideListener() {
                 @Override