1 files changed, 1 insertions, 1 deletions
diff --git a/src/doc/intro.md b/src/doc/intro.md
index 5be97034357..a4e9d85bffd 100644
--- a/src/doc/intro.md
+++ b/src/doc/intro.md
@@ -483,7 +483,7 @@ fn main() {
     for i in range(0u, 3u) {
         let number = numbers.clone();
         Thread::spawn(move || {
-            let mut array = number.lock();
+            let mut array = number.lock().unwrap();
 
             (*array)[i] += 1;