diff --git a/slides/cours_12.md b/slides/cours_12.md
index 825a674a5f0b11eb80c346e47f4ad0353016b066..1516fa9e767fd82c72935370a5003791f94c6ebf 100644
--- a/slides/cours_12.md
+++ b/slides/cours_12.md
@@ -62,8 +62,8 @@ typedef struct _queue {    // File d'attente:
 ```C
 void queue_init(queue *fa); // head = tail = NULL
 bool queue_is_empty(queue fa); // fa.head == fa.tail == NULL
-int queue_tail(queue fa); // return fa.head->data
-int queue_head(queue fa); // return fa.tail->data
+int queue_tail(queue fa); // return fa.tail->data
+int queue_head(queue fa); // return fa.head->data
 ```
 
 ## Manipulations et destruction