diff --git a/examples/01_introduction/04_Null Safety.md b/examples/01_introduction/04_Null Safety.md
index 5279a9e..17c1e3e 100755
--- a/examples/01_introduction/04_Null Safety.md	
+++ b/examples/01_introduction/04_Null Safety.md	
@@ -20,9 +20,9 @@ fun main() {
     fun strLength(notNull: String): Int {                   // 7
         return notNull.length
     }
-    
-    strLength(neverNull)                                    // 8
-    strLength(nullable)                                     // 9
+    println(strLength(neverNull));                           // 8
+println(strLength(nullable));                                // 9
+                                      
 //sampleEnd
 }
 ```