diff --git a/doc/ref/spec.md b/doc/ref/spec.md
index 300e5d9..7daf5e1 100644
--- a/doc/ref/spec.md
+++ b/doc/ref/spec.md
@@ -2258,7 +2258,7 @@
 
 Strings can be concatenated using the `+` operator:
 ```
-s := "hi " + name + " and good bye"
+s: "hi " + name + " and good bye"
 ```
 String addition creates a new string by concatenating the operands.