diff --git a/src/variable_bindings/mut.md b/src/variable_bindings/mut.md
index 0925132f20..c75f034ecd 100644
--- a/src/variable_bindings/mut.md
+++ b/src/variable_bindings/mut.md
@@ -15,9 +15,8 @@ fn main() {
 
     println!("After mutation: {}", mutable_binding);
 
-    // Error!
+    // Error! Cannot assign a new value to an immutable variable
     _immutable_binding += 1;
-    // FIXME ^ Comment out this line
 }
 ```