diff --git a/tools/cli/installers/lib/ide/codex-skills.js b/tools/cli/installers/lib/ide/codex-skills.js
index a5cb64b24..e82d04e51 100644
--- a/tools/cli/installers/lib/ide/codex-skills.js
+++ b/tools/cli/installers/lib/ide/codex-skills.js
@@ -125,7 +125,7 @@ class CodexSkillsSetup extends BaseIdeSetup {
       const skillContent = this.transformToSkillFormat(artifact.content, skillName);
 
       // Write SKILL.md
-      await fs.writeFile(path.join(skillDir, 'SKILL.md'), skillContent);
+      await fs.writeFile(path.join(skillDir, 'SKILL.md'), skillContent, 'utf8');
       writtenCount++;
     }