diff --git a/slides/cours_10.md b/slides/cours_10.md
index 4de7dc25d0b946599d8832e17b79336c563ac8c4..e52cec76eac0fc28529cc5329abd7333867c839d 100644
--- a/slides/cours_10.md
+++ b/slides/cours_10.md
@@ -690,7 +690,7 @@ Caractère lu        Pile opérandes
 . . .
 
 ```C
-bool evaluate(char *postfix, double *val) { // init stack
+double evaluate(char *postfix) { // init stack
     for (size_t i = 0; i < strlen(postfix); ++i) {
         if (is_operand(postfix[i])) {
             stack_push(&s, postfix[i]);