diff --git a/codes/c/utils/print_util.h b/codes/c/utils/print_util.h
index 7a71a3ce8..534b55870 100644
--- a/codes/c/utils/print_util.h
+++ b/codes/c/utils/print_util.h
@@ -64,8 +64,8 @@ typedef struct Trunk {
 Trunk *newTrunk(Trunk *prev, char *str) {
     Trunk *trunk = (Trunk *)malloc(sizeof(Trunk));
     trunk->prev = prev;
-    trunk->str = (char *)malloc(sizeof(char) * 10);
-    strcpy(trunk->str, str);
+    trunk->str = (char *)malloc(strlen(str) + 1);
+    snprintf(trunk->str, strlen(str) + 1, "%s", str);
     return trunk;
 }