diff --git a/variables/variables3.rs b/variables/variables3.rs
index ec55a951..0be8cb82 100644
--- a/variables/variables3.rs
+++ b/variables/variables3.rs
@@ -1,7 +1,7 @@
 // Make me compile! Scroll down for hints :)
 
 fn main() {
-    let x = 3;
+    let mut x = 3;
     println!("Number {}", x);
     x = 5;
     println!("Number {}", x);