diff --git a/module/documents/chat-message.mjs b/module/documents/chat-message.mjs
index d9f8b6c..43a6a38 100644
--- a/module/documents/chat-message.mjs
+++ b/module/documents/chat-message.mjs
@@ -1,10 +1,23 @@
 export default class HamalronChatMessage extends ChatMessage {
+  /** @override */
+  prepareDerivedData() {
+    if (this._source?.rolls) {
+      for (const r of this._source.rolls) {
+        try {
+          Roll.parse(r.formula || "1d6")
+        } catch (e) {
+          r.formula = "1d6"
+        }
+      }
+    }
+    super.prepareDerivedData()
+  }
+
   async _renderRollContent(messageData) {
     const data = messageData.message
     const { default: HamalronTirageTarot } = await import("./tirage-tarot.mjs")
     if (this.rolls[0] instanceof HamalronTirageTarot) {
       const isPrivate = !this.isContentVisible
-      // _renderRollHTML va appeler render sur tous les rolls
       const rollHTML = await this._renderRollHTML(isPrivate)
       if (isPrivate) {
         data.flavor = game.i18n.format("CHAT.PrivateRollContent", { user: this.user.name })