diff --git a/analyseur.c b/analyseur.c
index 99c2815..f60773f 100644
--- a/analyseur.c
+++ b/analyseur.c
@@ -415,15 +415,22 @@ void analyser_bigrammes(char **lignes, int nb_lignes,
 
 char *construire_rapport(const Entree *table, int n)
 {
-    char *rapport = malloc((size_t)n * 64 + 256);
-    char ligne[128];
-    rapport[0] = '\0';
-
-    ajouter(rapport, "rang;mot;occurrences\n");
+    size_t capacite = (size_t)n * 64 + 256;
+    char *rapport = malloc(capacite);
+    if (rapport == NULL) {
+        perror("malloc rapport");
+        exit(EXIT_FAILURE);
+    }
+    size_t position = (size_t)snprintf(rapport, capacite, "rang;mot;occurrences\n");
     for (int i = 0; i < n; i++) {
-        snprintf(ligne, sizeof(ligne), "%d;%s;%d\n",
-                 i + 1, table[i].mot, table[i].occurrences);
-        ajouter(rapport, ligne);
+        int taille = snprintf(rapport + position, capacite - position,
+                             "%d;%s;%d\n", i + 1, table[i].mot, table[i].occurrences);
+        if (taille < 0 || (size_t)taille >= capacite - position) {
+            fputs("Rapport trop long\n", stderr);
+            free(rapport);
+            exit(EXIT_FAILURE);
+        }
+        position += (size_t)taille;
     }
     return rapport;
 }